Release Notes
-This is a beta release of SCons, a tool for building software (and other
-files). SCons is implemented in Python, and its "configuration files"
-are actually Python scripts, allowing you to use the full power of a
-real scripting language to solve build problems. You do not, however,
-need to know Python to use SCons effectively.
+This is SCons, a tool for building software (and other files). SCons is
+implemented in Python, and its "configuration files" are actually Python
+scripts, allowing you to use the full power of a real scripting language
+to solve build problems. You do not, however, need to know Python to
+use SCons effectively.
So that everyone using SCons can help each other learn how to use it
-more effectively, please sign up for the scons-users mailing list at:
+more effectively, please sign up for the scons-users mailing list using
+the instructions on the following page:
- http://lists.sourceforge.net/lists/listinfo/scons-users
+ http://scons.org/lists.php
-RELEASE 0.97 - XXX
+RELEASE 1.3.0 - Tue, 23 Mar 2010 21:44:19 -0400
- This is a pre-release for testing the eighth beta release of SCons.
Please consult the CHANGES.txt file for a list of specific changes
since last release.
- Please note the following important changes since release 0.96:
+ Please note the following important changes in this release:
+
+ -- DEPRECATED FEATURES WILL GENERATE MANDATORY WARNINGS IN 1.3.0
+
+ In keeping with our deprecation cycle, the following deprecated
+ features will still be supported in 1.3.0 but will generate
+ mandatory, non-disableable warnings:
+
+ -- Support for Python versions 1.5, 1.6, 2.0, 2.1, 2.2, and 2.3.
+ -- The overrides= keyword argument to the Builder() call.
+ -- The scanner= keyword argument to the Builder() call.
+ -- The BuildDir() function and env.BuildDir() method.
+ -- The env.Copy() method.
+ -- The SourceSignatures() function and
+ env.SourceSignatures() method.
+ -- The TargetSignatures() function and
+ env.TargetSignatures() method.
+ -- The Sig module (now an unnused stub).
+ -- The --debug=dtree, --debug=stree and --debug=tree options.
+ -- The --debug=nomemoizer option.
+ -- The Options object and the related BoolOption(),
+ EnumOption(), ListOption(), PackageOption() and
+ PathOption() functions.
+
+ The mandatory warnings will be issued in order to make sure
+ users of 1.3.0 notice *prior* to the release of SCons 2.0.0, that
+ these features will be removed. In SCons 2.0.0 these features
+ will no longer work at all, and will instead generate specific
+ fatal errors when anyone tries to use them.
+
+ Please note the following important changes since release 1.2.0:
+
+ -- MICROSOFT VISUAL STUDIO VERSION/ARCH DETECTION HAS CHANGED
+
+ The way SCons detects Visual Studio on Windows has changed in
+ 1.3. By default, it should now use the latest installed
+ Visual Studio version on your machine, and compile for 32 or
+ 64 bits according to whether your OS is 32 or 64 bits (32/64
+ bit python makes no difference).
+
+ Two new variables control Visual Studio: MSVC_VERSION and
+ TARGET_ARCH. These variables ONLY take effect when passed to
+ the Environment() constructor; setting them later has no
+ effect. To use a non-default Visual Studio version, set
+ MSVC_VERSION to e.g. "8.0" or "7.1". Setting it to "xxx" (or
+ any nonexistent value) will make it print out the valid
+ versions on your system. To use a non-default architecture,
+ set TARGET_ARCH to "x86" or "x86_64" (various synonyms are
+ accepted).
- - The ParseConfig() method now adds library file names returned
- by the specified *-config command to the $LIBS construction
- variable, instead of returning them (the same way it handles
- the -l option).
-
- - By default, the ParseConfig() method now avoids adding duplicate
- entries to construction variables. The old behavior may be
- specified using a new "unique=0" keyword argument.
-
- - Custom builders that accept directories as source arguments no
- longer scan entire directory trees by default. This means that
- their targets will not be automatically rebuilt if a file that
- SCons does *not* already know about changes on disk. Note that
- the targets *will* still be rebuilt correctly if a file changes
- that SCons already knows about due to a Builder or other call.
-
- The existing behavior of scanning directory trees for any changed
- file on-disk can be maintained by passing the new DirScanner global
- directory scanner as the source_scanner keyword argument to the
- Builder call:
-
- bld = Builder("build < $SOURCE > $TARGET",
- source_scanner = DirScanner)
-
- The same keyword argument can also be supplied to any Command()
- calls that need to scan directory trees on-disk for changed files:
-
- env.Command("archive.out", "directory",
- "archiver -o $TARGET $SOURCE",
- source_scanner = DirScanner)
-
- - When compiling with Microsoft Visual Studio, SCons no longer
- adds the ATL and MFC directories to the INCLUDE and LIB
- environment variables by default. If you want these directories
- included in your environment variables, you should now set the
- $MSVS_USE_MFC_DIRS *construction* variable when initializing
- your environment:
-
- env = Environment(MSVS_USE_MFC_DIRS = 1)
-
- - The following deprecated global functions have been removed:
- ParseConfig(), SetBuildSignatureType(), SetContentSignatureType(),
- SetJobs() and GetJobs().
-
- - The deprecated "validater" keyword to the Options.Add() method
- has been removed.
-
- - The %TEMP% and %TMP% external environment variables are now
- propagated automatically to the command execution environment on
- Windows systems.
-
- - The Configure() subsystem now reports tests results as "yes" and
- "no" instead of "ok" and "failed." This might interfere with any
- scripts that automatically parse the Configure() output from SCons.
-
- - The Configure() subsystem now stores its cached results in a
- different file. This may cause configuration tests to be re-run
- the first time after you install 0.97.
-
- Please note the following important changes since release 0.95:
-
- - All Builder calls (both built-in like Program(), Library(),
- etc. and customer Builders) now always return a list of target
- Nodes. If the Builder only builds one target, the Builder
- call will now return a list containing that target Node, not
- the target Node itself as it used to do.
-
- This change should be invisibile to most normal uses of the
- return values from Builder calls. It will cause an error if the
- SConscript file was performing some direct manipulation of the
- returned Node value. For example, an attempt to print the name
- of a target returned by the Object() Builder:
-
- target = Object('foo.c')
- # OLD WAY
- print target
-
- Will now need to access the first element in the list returned by
- the Object() call:
-
- target = Object('foo.c')
- # NEW AY
- print target[0]
-
- This change was introduced to make the data type returned by Builder
- calls consistent (always a list), regardless of platform or number
- of returned targets.
-
- - The SConsignFile() function now uses an internally-supplied
- SCons.dblite module as the default DB scheme for the .sconsign file.
- If you are using the SConsignFile() function without an explicitly
- specified dbm_module argument, this will cause all of your targets
- to be recompiled the first time you use SCons 0.96. To preserve the
- previous behavior, specify the "anydbm" module explicitly:
-
- import anydbm
- SConsignFile('.sconsign_file_name', anydbm)
-
- - The internal format of .sconsign files has been changed. This might
- cause warnings about "ignoring corrupt .sconsign files" and rebuilds
- when you use SCons 0.96 for the first time in a tree that was
- previously built with SCons 0.95 or earlier.
-
- - The scan_check function that can be supplied to a custom Scanner now
- must take two arguments, the Node to be checked and a construction
- environment. It previously only used the Node as an argument.
-
- - The internal Scanner.add_skey() method no longer works for the
- default scanners, which now use construction variables to hold their
- lists of suffixes. If you had a custom Tool specification that was
- reaching into the internals in this way to add a suffix to one of
- the following scanner, you must now add the suffix to a construction
- environment through which you plan to call the scanner, as follows:
-
- CScan.add_skey('.x') => env.Append(CPPSUFFIXES = ['.x'])
- DScan.add_skey('.x') => env.Append(DSUFFIXES = ['.x'])
- FortranScan.add_skey('.x') => env.Append(FORTRANSUFFIXES = ['.x'])
-
- - The "node_factory" and "scanner" keyword arguments to the Builder()
- function have been removed. In their place, the separate and more
- flexible "target_factory," "source_factory," "target_scanner" and
- "source scanner" keywords should be used instead.
-
- - SCons now treats file "extensions" that contain all digits (for
- example, "file.123") as part of the file basename, for easier
- handling of version numbers in the names of shared libraries
- and other files. Builders will now add their file extensions to
- file names specified with all-digit extensions. If you need to
- generate a file with an all-digit extension using a Builder that
- adds a file extension, you can preserve the previous behavior by
- wrapping the file name in a File() call.
-
- - The behavior of the env.Append() and env.Prepend() methods has
- changed when appending a string value to a UserList, or vice versa.
- They now behave like normal Python addition of a string to
- a UserList. Given an initialization and an env.Append() call like:
-
- env = Environment(VAR1=UserList(['foo']), VAR2='foo')
- env.Append(VAR1='bar', VAR2=UserList(['bar'])
-
- The resulting values of $VAR1 and $VAR2 will now be ['foo', 'b',
- 'a', 'r'] and ['f', 'o', 'o', 'bar'], respectively. This is because
- Python UserList objects treat strings as sequences of letters when
- adding them to the value of the UserList.
-
- The old behavior of yielding $VAR1 and $VAR2 values of ['foo',
- 'bar'] when either variable is a UserList object now requires that
- the string variables be enclosed in a list:
-
- env = Environment(VAR1=UserList(['foo']), VAR2=['foo'])
- env.Append(VAR1='bar', VAR2=UserList(['bar']))
-
- Note that the SCons behavior when appending to normal lists has
- *not* changed, and the behavior of all of the default values that
- SCons uses to initialize all construction variables has *not*
- changed. This change *only* affects any cases where you explicitly
- use UserList objects to initialize or append to a variable.
+ In addition, MSVC_USE_SCRIPT can be used to bypass the
+ above autodetection; setting it to the path of a Visual
+ Studio .bat file (e.g. vcvars.bat) will cause SCons to
+ run that bat file and extract the relevant variables
+ from the result (typically %INCLUDE%, %LIB%, and %PATH%).
+ Setting MSVC_USE_SCRIPT to None bypasses the Visual Studio
+ autodetection entirely; use this if you are importing
+ the shell env and running SCons in a Visual Studio cmd window.
+
+ Note that if you use MSVS_VERSION to build Visual Studio
+ projects from your SConstructs, MSVS_VERSION must be set to
+ the same version as MSVC_VERSION.
+
+ Support for HOST_OS,HOST_ARCH,TARGET_OS, TARGET_ARCH has been
+ added to allow specifying different target arch than the host
+ system. This is only supported for Visual Studio/Visual C++
+ at this time.
+
+ -- Support for Latex glossaries and acronyms has been added
+
+ -- VISUAL C/C++ PRECOMPILED HEADERS WILL BE REBUILT
+
+ Precompiled header files built with Visual C/C++ will be
+ rebuilt after upgrading from 1.2.0 to a later release.
+
+ This rebuild is normal and will occur because the command line
+ defined by the $PCHCOM construction variable has had the $CCFLAGS
+ variable added, and has been rearranged to put the "/Fo" output
+ flag towards the beginning of the line, consistent with the
+ related command lines for $CCCOM, $CXXCOM, etc.
+
+ -- CHANGES TO SOME LINKER COMMAND LINES WILL CAUSE RELINKING
+
+ Changes to the command line definitions for the Microsoft link.exe
+ linker, the OS/2 ilink linker and the Phar Lap linkloc linker
+ will cause targets built with those tools be to be rebuilt after
+ upgrading from 1.2.0 to a later release.
+
+ This relink is normal and will occur because the command lines for
+ these tools have been redefined to remove unnecessary nested $(
+ and $) character strings.
+
+ -- MSVS_USE_MFC_DIRS and MSVS_IGNORE_IDE_PATHS are obsoleted and
+ have no effect.
+
+ Please note the following important changes since release 1.1.0:
+
+ -- THE $CHANGED_SOURCES, $CHANGED_TARGETS, $UNCHANGED_SOURCES
+ AND $UNCHANGED_TARGETS VARIABLES WILL BECOME RESERVED
+
+ A future release (probably 1.3.0) will make the construction
+ variable names $CHANGED_SOURCES, $CHANGED_TARGETS,
+ $UNCHANGED_SOURCES and $UNCHANGED_TARGETS into reserved
+ construction variable names controlled by SCons itself (like
+ the current $SOURCE, $TARGETS, etc.).
+
+ Setting these variable names in the current release will generate
+ a warning but still set the variables. When they become reserved
+ variable names, they will generate a different warning message
+ and attempts to set these variables will be ignored.
+
+ SCons configurations that happen to use these variable names
+ should be changed to use different variable names, in order
+ to ensure that the configuration continues to work with future
+ versions of SCons.
+
+ -- THE Options OBJECT AND RELATED FUNCTIONS NOW GENERATE WARNINGS
+
+ Use of the Options object, and related functions BoolOption(),
+ EnumOption(), ListOption(), PackageOption() and PathOption()
+ were announced as deprecated in release 0.98.1. Since then,
+ however, no warning messages were ever implemented for the
+ use of these deprecated functions.
+
+ By default, release 1.2.0 prints warning messages when these
+ deprecated features are used. Warnings about all deprecated
+ features may be suppressed by using the --warn=no-deprecated
+ command-line option:
+
+ $ scons --warn=no-deprecated
+
+ Or by using the appropriate SetOption() call in any SConscript
+ file:
+
+ SetOption('warn', 'no-deprecated')
+
+ You may optionally disable just warnings about the deprecation
+ of the Options object and its related functions as follows:
+
+ SetOption('warn', 'no-deprecated-options')
+
+ The current plan is for these warnings to become mandatory
+ (non-suppressible) in release 1.3.0, and for the use of Options
+ and its related functions to generate errors in release 2.0.
+
+ Please note the following important changes since release 0.98.4:
+
+ -- scons.bat NOW RETURNS THE REAL SCONS EXIT STATUS
+
+ The scons.bat script shipped with SCons used to exit with
+ a status of 1 when it detected any failed (non-zero) exit
+ status from the underlying Python execution of SCons itself.
+ The scons.bat script now exits with the actual status
+ returned by SCons.
+
+ -- SCONS NOW WARNS WHEN TRYING TO LINK C++ AND FORTRAN OBJECT FILES
+
+ Some C++ toolchains do not understand Fortran runtimes and create
+ unpredictable executables when linking C++ and Fortran object
+ files together. SCons now issues a warning if you try to link
+ C++ and Fortran object files into the same executable:
+
+ scons: warning: Using $CXX to link Fortran and C++ code together.
+ This may generate a buggy executable if the '/usr/bin/gcc'
+ compiler does not know how to deal with Fortran runtimes.
+
+ The warning may be suppressed with either the --warning=no-link
+ or --warning=no-fortran-cxx-mix command line options, or by
+ adding either of the following lines to a SConscript file:
+
+ SetOption('warn', 'no-link')
+ SetOption('warn', 'no-fortran-cxx-mix')
+
+ Please note the following important changes since release 0.98:
+
+ -- SCONS NO LONGER SETS THE GNU TOOLCHAIN -fPIC FLAG IN $SHCXXFLAGS
+
+ The GNU toolchain support in previous versions of SCons would
+ add the -fPIC flag to the $SHCXXFLAGS construction variable.
+ The -fPIC flag has been now been removed from the default
+ $SHCXXFLAGS setting. Instead, the $SHCXXCOM construction variable
+ (the default SCons command line for compiling shared objects
+ from C++ source files) has been changed to add the $SHCCFLAGS
+ variable, which contains the -fPIC flag.
+
+ This change was made in order to make the behavior of the default
+ C++ compilation line including $SHCCFLAGS consistent with the
+ default C compilation line including $CCFLAGS.
+
+ This change should have no impact on configurations that use
+ the default $SHCXXCOM command line. It may have an impact on
+ configurations that were using the default $SHCXXFLAGS value
+ *without* the $SHCCFLAGS variable to get the -fPIC flag into a
+ custom command line. You can fix these by adding the $SHCCFLAGS
+ to the custom command line.
+
+ Adding $SHCCFLAGS is backwards compatible with older SCons
+ releases, although it might cause the -fPIC flag to be repeated
+ on the command line if you execute it on an older version of
+ SCons that sets -fPIC in both the $SHCCLAFGS and $SHCXXFLAGS
+ variables. Duplicating the -fPIC flag on the g++ command line
+ will not cause any compilation problems, but the change to the
+ command line may cause SCons to rebuild object files.
+
+ -- FORTRAN NOW COMPILES .f FILES WITH gfortran BY DEFAULT
+
+ The Fortran Tool modules have had a major overhaul with the intent
+ of making them work as-is for most configurations. In general,
+ most configurations that use default settings should not see
+ any noticeable difference.
+
+ One configuration that has changed is if you have both a gfortran
+ and g77 compiler installed. In this case, previous versions of
+ SCons would, by default, use g77 by default to compile files with
+ a .f suffix, while SCons 0.98.1 will use the gfortran compiler
+ by default. The old behavior may be preserved by explicitly
+ initializing construction environments with the 'g77' Tool module:
+
+ env = Environment(tools = ['g77', 'default'])
+
+ The above code is backwards compatible to older versions of SCons.
+
+ If you notice any other changes in the behavior of default
+ Fortran support, please let us know so we can document them in
+ these release notes for other users.
+
+ Please note the following important changes since release 0.97.0d20071212:
+
+ -- SUPPORT FOR PYTHON VERSIONS BEFORE 2.2 IS NOW DEPRECATED
+
+ SCons now prints the following warning when it is run by any
+ Python 1.5, 2.0 or 2.1 release or sub-release:
+
+ scons: warning: Support for pre-2.2 Python (VERSION) is deprecated.
+ If this will cause hardship, contact dev@scons.tigris.org.
+
+ You may disable all warnings about deprecated features by adding
+ the option "--warn=no-deprecated" to the command line or to the
+ $SCONSFLAGS environment variable:
+
+ $ scons --warn=no-deprecated
+
+ Using '--warn=no-deprecated' is compatible with earlier versions
+ of SCons.
+
+ You may also, as of this version of SCons, disable all warnings
+ about deprecated features by adding the following to any
+ SConscript file:
+
+ SetOption('warn', 'no-deprecated')
+
+ You may disable only the specific warning about running under
+ a deprecated Python version by adding the following to any
+ SConscript file:
+
+ SetOption('warn', 'no-python-version')
+
+ The warning may also be suppressed on the command line:
+
+ $ scons --warn=no-python-version
+
+ Or by specifying the --warn=no-python-version option in the
+ $SCONSFLAGS environment variable.
+
+ Using SetOption('warn', ...), and the 'no-python-version'
+ command-line option for suppressing this specific warning,
+ are *not* backwards-compatible to earlier versions of SCons.
+
+ -- THE env.Copy() METHOD IS NOW OFFICIALLY DEPRECATED
+
+ The env.Copy() method is now officially deprecated and will
+ be removed in a future release. Using the env.Copy() method
+ now generates the following message:
+
+ scons: warning: The env.Copy() method is deprecated; use the env.Clone() method instead.
+
+ You may disable all warnings about deprecated features by adding
+ the option "--warn=no-deprecated" to the command line or to the
+ $SCONSFLAGS environment variable:
+
+ $ scons --warn=no-deprecated
+
+ Using '--warn=no-deprecated' is compatible with earlier versions
+ of SCons.
+
+ You may also, as of this version of SCons, disable all warnings
+ about deprecated features by adding the following to any
+ SConscript file:
+
+ SetOption('warn', 'no-deprecated')
+
+ You may disable only the specific warning about the deprecated
+ env.Copy() method by adding the following to any SConscript
+ file:
+
+ SetOption('warn', 'no-deprecated-copy')
+
+ The warning may also be suppressed on the command line:
+
+ $ scons --warn=no-deprecated-copy
+
+ Or by specifying the --warn=no-deprecated-copy option in the
+ $SCONSFLAGS environment variable.
+
+ Using SetOption('warn', ...), and the 'no-deprecated-copy'
+ command-line option for suppressing this specific warning,
+ are *not* backwards-compatible to earlier versions of SCons.
+
+ -- THE --debug=dtree, --debug=stree AND --debug=tree OPTIONS ARE DEPRECATED
+
+ The --debug=dtree, --debug=stree and --debug=tree methods
+ are now officially deprecated and will be removed in a
+ future release. Using these options now generate a warning
+ message recommending use of the --tree=derived, --tree=all,status
+ and --tree=all options, respectively.
+
+ You may disable these warnings, and all warnings about
+ deprecated features, by adding the option "--warn=no-deprecated"
+ to the command line or to the $SCONSFLAGS environment
+ variable:
+
+ $ scons --warn=no-deprecated
+
+ Using '--warn=no-deprecated' is compatible with earlier versions
+ of SCons.
+
+ -- THE TargetSignatures() AND SourceSignatures() FUNCTIONS ARE DEPRECATED
+
+ The TargetSignatures() and SourceSignatures() functions,
+ and their corresponding env.TargetSignatures() and
+ env.SourceSignatures() methods, are now officially deprecated
+ and will be be removed in a future release. Using ahy of
+ these functions or methods now generates a message
+ similar to the following:
+
+ scons: warning: The env.TargetSignatures() method is deprecated;
+ convert your build to use the env.Decider() method instead.
+
+ You may disable all warnings about deprecated features by adding
+ the option "--warn=no-deprecated" to the command line or to the
+ $SCONSFLAGS environment variable:
+
+ $ scons --warn=no-deprecated
+
+ Using '--warn=no-deprecated' is compatible with earlier versions
+ of SCons.
+
+ You may also, as of this version of SCons, disable all warnings
+ about deprecated features by adding the following to any
+ SConscript file:
+
+ SetOption('warn', 'no-deprecated')
+
+ You may disable only the specific warning about the use of
+ TargetSignatures() or SourceSignatures() by adding the
+ following to any SConscript file:
+
+ SetOption('warn', 'no-deprecated-target-signatures')
+ SetOption('warn', 'no-deprecated-source-signatures')
+
+ The warnings may also be suppressed on the command line:
+
+ $ scons --warn=no-deprecated-target-signatures --warn=no-deprecated-source-signatures
+
+ Or by specifying these options in the $SCONSFLAGS environment
+ variable.
+
+ Using SetOption('warn', ...), or the command-line options
+ for suppressing these warnings, is *not* backwards-compatible
+ to earlier versions of SCons.
+
+ -- File(), Dir() and Entry() NOW RETURN A LIST WHEN THE INPUT IS A SEQUENCE
+
+ Previously, if these methods were passed a list, the list was
+ substituted and stringified, then passed as a single string to
+ create a File/Dir/Entry Node. This rarely if ever worked with
+ more than one element in the list. They now return a list of
+ Nodes when passed a list.
+
+ One case that works differently now is a passing in a
+ single-element sequence; that formerly was stringified
+ (returning its only element) and then a single Node would be
+ returned. Now a single-element list containing the Node will
+ be returned, for consistency.
+
+ -- THE env.subst() METHOD NOW RETURNS A LIST WHEN THE INPUT IS A SEQUENCE
+
+ The env.subst() method now returns a list with the elements
+ expanded when given a list as input. Previously, the env.subst()
+ method would always turn its result into a string.
+
+ This behavior was changed because it interfered with being able
+ to include things like lists within the expansion of variables
+ like $CPPPATH and then have SCons understand that the elements
+ of the "internal" lists still needed to be treated separately.
+ This would cause a $CPPPATH list like ['subdir1', 'subdir']
+ to show up in a command line as "-Isubdir1 subdir".
+
+ -- THE Jar() BUILDER NOW USES THE Java() BUILDER CLASSDIR BY DEFAULT
+
+ By default, the Jar() Builder will now use the class directory
+ specified when the Java() builder is called. So the following
+ input:
+
+ classes = env.Java('classes', 'src')
+ env.Jar('out.jar', classes)
+
+ Will cause "-C classes" to be passed the "jar" command invocation,
+ and the Java classes in the "out.jar" file will not be prefixed
+ "classes/".
+
+ Explicitly setting the $JARCHDIR variable overrides this default
+ behavior. The old behavior of not passing any -C option to the
+ "jar" command can be preserved by explicitly setting $JARCHDIR
+ to None:
+
+ env = Environment(JARCHDIR = None)
+
+ The above setting is compatible with older versions of SCons.
+
+ Please note the following important changes since release 0.97.0d20070918:
+
+ -- SCons REDEFINES PYTHON open() AND file() ON Windows TO NOT PASS
+ ON OPEN FILE HANDLES TO CREATED PROCESSES
+
+ On Windows systems, SCons now redefines the Python open()
+ and file() functions so that, if the Python Win32 extensions
+ are available, the file handles for any opened files will *not*
+ be inherited by subprocesses, such as the spawned compilers and
+ other tools invoked to build the software.
+
+ This prevents certain race conditions where a file handle for
+ a file opened by Python (either in a Python function action,
+ or directly in a SConscript file) could be inherited and help
+ open by a subprocess, interfering with the ability of other
+ processes to create or modify the file.
+
+ In general, this should not cause problems for the vast majority
+ of configurations. The only time this would be a problem would be
+ in the unlikely event that a process spawned by SCons specifically
+ *expected* to use an inherited file handle opened by SCons.
+
+ If the Python Win32 extensions are not installed or are an
+ earlier version that does not have the ability to disable file
+ handle inheritance, SCons will print a warning message when the
+ -j option is used. The warning message may be suppressed by
+ specifying --warn=no-parallel-support.
+
+ Please note the following important changes since release 0.97.0d20070809:
+
+ -- "content" SIGNATURES ARE NOW THE DEFAULT BEHAVIOR
+
+ The default behavior of SCons is now to use the MD5 checksum of
+ all file contents to decide if any files have changed and should
+ cause rebuilds of their source files. This means that SCons may
+ decide not to rebuild "downstream" targets if a a given input
+ file is rebuilt to the exact same contents as the last time.
+ The old behavior may preserved by explicity specifying:
+
+ TargetSignatures("build")
+
+ In any of your SConscript files.
+
+ -- TARGETS NOW IMPLICITLY DEPEND ON THE COMMAND THAT BUILDS THEM
+
+ For all targets built by calling external commands (such as a
+ compiler or other utility), SCons now adds an implicit dependency
+ on the command(s) used to build the target.
+
+ This will cause rebuilds of all targets built by external commands
+ when running SCons in a tree built by previous version of SCons,
+ in order to update the recorded signatures.
+
+ The old behavior of not having targets depend on the external
+ commands that build them can be preserved by setting a new
+ $IMPLICIT_COMMAND_DEPENDENCIES construction variable to a
+ non-True value:
+
+ env = Environment(IMPLICIT_COMMAND_DEPENDENCIES = 0)
+
+ or by adding Ignore() calls for any targets where the behavior
+ is desired:
+
+ Ignore('/usr/bin/gcc', 'foo.o')
+
+ Both of these settings are compatible with older versions
+ of SCons.
+
+ -- CHANGING SourceSignature() MAY CAUSE "UNECESSARY" REBUILDS
+
+ If you change the SourceSignature() value from 'timestamp' to
+ 'MD5', SCons will now rebuild targets that were already up-to-date
+ with respect to their source files.
+
+ This will happen because SCons did not record the content
+ signatures of the input source files when the target was last
+ built--it only recorded the timestamps--and it must record them
+ to make sure the signature information is correct. However,
+ the content of source files may have changed since the last
+ timestamp build was performed, and SCons would not have any way to
+ verify that. (It would have had to open up the file and record
+ a content signature, which is one of the things you're trying to
+ avoid by specifying use of timestamps....) So in order to make
+ sure the built targets reflect the contents of the source files,
+ the targets must be rebuilt.
+
+ Change the SourceSignature() value from 'MD5' to 'timestamp'
+ should correctly not rebuild target files, because the timestamp
+ of the files is always recorded.
+
+ In previous versions of SCons, changing the SourceSignature()
+ value would lead to unpredictable behavior, usually including
+ rebuilding targets.
+
+ -- THE Return() FUNCTION NOW ACTUALLY RETURNS IMMEDIATELY
+
+ The Return() function now immediately stops processing the
+ SConscript file in which it appears and returns the values of the
+ variables named in its arguments. It used to continue processing
+ the rest of the SConscript file, and then return the values of the
+ specified variables at the point the Return() function was called.
+
+ The old behavior may be requested by adding a "stop=False"
+ keyword argument to the Return() call:
+
+ Return('value', stop=False)
+
+ The "stop=" keyword argument is *not* compatible with SCons
+ versions 0.97.0d20070809 or earlier.
+
+ Please note the following important changes since release 0.97:
+
+ -- env.CacheDir() NOW ONLY AFFECTS CONSTRUCTION ENVIRONMENT TARGETS
+
+ The env.CacheDir() method now only causes derived files to be
+ retrieved from the specified cache directory for targets built
+ with the specified specified construction environment ("env").
+
+ Previously, any call to env.CacheDir() or CacheDir() would modify
+ a global setting and cause all built targets to be retrieved
+ from the specified cache directory. This behavior was changed so
+ that env.CacheDir() would be consistent with other construction
+ environment methods, which only affect targets built with the
+ specified construction environment.
+
+ The old behavior of changing the global behavior may be preserved
+ by changing any env.CacheDir() calls to:
+
+ CacheDir('/path/to/cache/directory')
+
+ The above change is backwards-compatible and works in all earlier
+ versions of SCons that support CacheDir().
+
+ -- INTERPRETATION OF SUFFIX-LESS SOURCE ARGUMENTS HAS CHANGED
+
+ The interpretation of source arguments (files) without suffixes
+ has changed in one specific configuration.
+
+ Previously, if a Builder had a src_suffix specified (indicating
+ that source files without suffixes should have that suffix
+ appended), the suffix would only be applied to suffix-less source
+ arguments if the Builder did *not* have one or more attached
+ source Builders (that is, the Builder was not a "multi-stage"
+ Builder). So in the following configuration:
+
+ build_foo = Builder(src_suffix = '.foo')
+ build_bar = Builder(src_suffix = '.bar',
+ src_builder = build_bar)
+
+ env = Environment(BUILDERS = {
+ 'Foo' : build_foo,
+ 'Boo' : build_bar,
+ })
+
+ env.Foo('tgt1', 'src1')
+ env.Bar('tgt2', 'src2')
+
+ SCons would have expected to find a source file 'src1.foo' for the
+ env.Foo() call, but a source file 'src2' for the env.Bar() call.
+
+ This behavior has now been made consistent, so that the two
+ above calls would expect source files named 'src1.foo' and
+ 'src2.bar', respectively.
+
+ Note that, if genuinely desired, the old behavior of building
+ from a source file without a suffix at all (when the Builder has
+ a src_suffix *and* a src_builder) can be specified explicity by
+ turning the string into a File Node directly:
+
+ env.Bar('tgt2', File('src2'))
+
+ The above use of File() is backwards-compatible and will work
+ on earlier versions of SCons.
+
+ -- THE DEFAULT EXECUTION PATH FOR Solaris HAS CHANGED
+
+ On Solaris systems, SCons now adds the "/opt/SUNWspro/bin"
+ directory to the default execution $PATH variable before the
+ "/usr/ccs/bin" directory. This was done to reflect the fact
+ that /opt/SUNWspro/ is the default for SUN tools, but it may
+ cause a different compiler to be used if you have compilers
+ installed in both directories.
+
+ -- GENERATED config.h FILES NOW SAY "#define HAVE_{FEATURE} 1"
+
+ When generating a "config.h" file, SCons now defines values that
+ record the existence of a feature with a "1" value:
+
+ #define HAVE_FEATURE 1
+
+ Instead of printing the line without a "1", as it used to:
+
+ #define HAVE_FEATURE
+
+ This should not cause any problems in the normal use of "#ifdef
+ HAVE_{FEATURE}" statements interpreted by a C preprocessor, but
+ might cause a compatibility issue if a script or other utility
+ looks for an exact match of the previous text.
Please note the following planned, future changes:
- - Several internal variable names in SCons.Defaults for various
- pre-made default Scanner objects have been deprecated and will
- be removed in a future revision. In their place are several new
- global variable names that are now part of the publicly-supported
- interface:
+ -- THE Options OBJECT AND RELATED FUNCTIONS WILL BE DEPRECATED
+
+ The Options object is being replaced by a new Variables
+ object, which uses a new Variables.AddVariable() method
+ where the previous interface used Options.AddOptions().
+
+ Similarly, the following utility functions are being replaced
+ by the following similarly-named functions:
+
+ BoolOption() BoolVariable()
+ EnumOption() EnumVariable()
+ ListOption() ListVariable()
+ PackageOption() PackageVariable()
+ PathOption() PathVariable()
+
+ And also related, the options= keyword argument when creating
+ construction environments with the Environment() functions is
+ being replaced with a variables= keyword argument.
+
+ In some future release a deprecation warning will be added to
+ existing uses of the Options object, its methods, the above
+ utility functions, and the options= keyword argument of the
+ Environment() function. At some point after the deprecation
+ warning is added, the Options object, related functions and
+ options= keyword argument will be removed entirely.
+
+ You can prepare for this by changing all your uses of the Options
+ object and related functions to the Variables object and the new
+ function names, and changing any uses of the options= keyword
+ argument to variables=.
+
+ NOTE: CONVERTING TO USING THE NEW Variables OBJECT OR THE
+ RELATED *Variable() FUNCTIONS, OR USING THE NEW variable=
+ KEYWORD ARGUMENT, IS NOT BACKWARDS COMPATIBLE TO VERSIONS OF
+ SCons BEFORE 0.98. YOUR SConscript FILES WILL NOT WORK ON
+ EARLIER VERSIONS OF SCons AFTER MAKING THIS CHANGE.
+
+ If you change SConscript files in software that you make available
+ for download or otherwise distribute, other users may try to
+ build your software with an earlier version of SCons that does
+ not have the Variables object or related *Variable() functions.
+ We recommend preparing for this in one of two ways:
+
+ -- Make your SConscript files backwards-compatible by
+ modifying your calls with Python try:-except: blocks
+ as follows:
+
+ try:
+ vars = Variables('custom.py', ARGUMENTS)
+ vars.AddVariables(
+ BoolVariable('WARNINGS', 'cmopile with -Wall', 1),
+ EnumVariable('DEBUG', 'debug version', 'no'
+ allowed_values=('yes', 'no', 'full'),
+ map={}, ignorecase=0),
+ ListVariable('SHAREDLIBS',
+ 'libraries to build shared',
+ 'all',
+ names = list_of_libs),
+ PackageVariable('X11',
+ 'use X11 from here',
+ '/usr/bin/X11'),
+ PathVariable('QTDIR', 'root of Qt', qtdir),
+ )
+ except NameError:
+ vars = Options('custom.py', ARGUMENTS)
+ vars.AddOptions(
+ BoolOption('WARNINGS', 'cmopile with -Wall', 1),
+ EnumOption('DEBUG', 'debug version', 'no'
+ allowed_values=('yes', 'no', 'full'),
+ map={}, ignorecase=0),
+ ListOption('SHAREDLIBS',
+ 'libraries to build shared',
+ 'all',
+ names = list_of_libs),
+ PackageOption('X11',
+ 'use X11 from here',
+ '/usr/bin/X11'),
+ PathOption('QTDIR', 'root of Qt', qtdir),
+ )
+
+ Additionally, you can check for availability of the new
+ variables= keyword argument as follows:
+
+ try:
+ env = Environment(variables=vars)
+ except TypeError:
+ env = Environment(options=vars)
+
+ (Note that we plan to maintain the existing Options object
+ name for some time, to ensure backwards compatibility,
+ so in practice it may be easier to just continue to use
+ the old name until you're reasonably sure you won't have
+ people trying to build your software with versions of
+ SCons earlier than 0.98.1.)
+
+ -- Use the EnsureSConsVersion() function to provide a
+ descriptive error message if your SConscript files
+ are executed by an earlier version of SCons:
+
+ EnsureSConsVersion(0, 98, 1)
+
+ -- THE BuildDir() METHOD AND FUNCTION WILL BE DEPRECATED
+
+ The env.BuildDir() method and BuildDir() function are being
+ replaced by the new env.VariantDir() method and VariantDir()
+ function.
+
+ In some future release a deprecation warning will be added
+ to existing uses of the env.BuildDir() method and BuildDir()
+ function. At some point after the deprecation warning, the
+ env.Builder() method and BuildDir() function will either
+ be removed entirely or have their behavior changed.
+
+ You can prepare for this by changing all your uses of the
+ env.BuildDir() method to env.VariantDir() and uses of the
+ global BuildDir() function to VariantDir(). If you use a
+ named keyword argument of "build_dir" when calling
+ env.BuildDir() or BuildDir():
+
+ env.BuildDir(build_dir='opt', src_dir='src')
+
+ The keyword must be changed to "variant_dir":
+
+ env.VariantDir(variant_dir='opt', src_dir='src')
+
+ NOTE: CHANGING USES OF env.BuildDir() AND BuildDir() to
+ env.VariantDir() AND VariantDir() IS NOT BACKWARDS COMPATIBLE
+ TO VERSIONS OF SCons BEFORE 0.98. YOUR SConscript FILES
+ WILL NOT WORK ON EARLIER VERSIONS OF SCons AFTER MAKING
+ THIS CHANGE.
+
+ If you change SConscript files in software that you make
+ available for download or otherwise distribute, other users
+ may try to build your software with an earlier version of
+ SCons that does not have the env.VariantDir() method or
+ VariantDir() fnction. We recommend preparing for this in
+ one of two ways:
+
+ -- Make your SConscript files backwards-compatible by
+ including the following code near the beginning of your
+ top-level SConstruct file:
+
+ import SCons.Environment
+ try:
+ SCons.Environment.Environment.VariantDir
+ except AttributeError:
+ SCons.Environment.Environment.VariantDir = \
+ SCons.Environment.Environment.BuildDir
+
+ -- Use the EnsureSConsVersion() function to provide a
+ descriptive error message if your SConscript files
+ are executed by an earlier version of SCons:
+
+ EnsureSConsVersion(0, 98)
+
+ -- THE SConscript() "build_dir" KEYWORD ARGUMENT WILL BE DEPRECATED
+
+ The "build_dir" keyword argument of the SConscript function
+ and env.SConscript() method are being replaced by a new
+ "variant_dir" keyword argument.
+
+ In some future release a deprecation warning will be added
+ to existing uses of the SConscript()/env.SConscript()
+ "build_dir" keyword argument. At some point after the
+ deprecation warning, support for this keyword argument will
+ be removed entirely.
+
+ You can prepare for this by changing all your uses of the
+ SConscript()/env.SConscript() 'build_dir" keyword argument:
+
+ SConscript('src/SConscript', build_dir='opt')
+
+ To use the new "variant_dir" keyword argument:
+
+ SConscript('src/SConscript', variant_dir='opt')
+
+ NOTE: USING THE NEW "variant_dir" KEYWORD IS NOT BACKWARDS
+ COMPATIBLE TO VERSIONS OF SCons BEFORE 0.98. YOUR SConscript
+ FILES WILL NOT WORK ON EARLIER VERSIONS OF SCons AFTER
+ MAKING THIS CHANGE.
+
+ If you change SConscript files in software that you make
+ available for download or otherwise distribute, other users
+ may try to build your software with an earlier version of
+ SCons that does not support the "variant_dir" keyword.
+
+ If you can insist that users use a recent version of SCons
+ that supports "variant_dir", we recommend using the
+ EnsureSConsVersion() function to provide a descriptive error
+ message if your SConscript files are executed by an earlier
+ version of SCons:
+
+ EnsureSConsVersion(0, 98)
+
+ If you want to make sure that your SConscript files will
+ still work with earlier versions of SCons, then your best
+ bet is to continue to use the "build_dir" keyword until the
+ support is removed (which, in all likelihood, won't happen
+ for quite some time).
- NEW NAME DEPRECATED NAME
- -------- ----------------------------
- CScanner SCons.Defaults.CScan
- DSCanner SCons.Defaults.DScan
- SourceFileScanner SCons.Defaults.ObjSourceScan
- ProgramScanner SCons.Defaults.ProgScan
+ -- SCANNER NAMES HAVE BEEN DEPRECATED AND WILL BE REMOVED
+
+ Several internal variable names in SCons.Defaults for various
+ pre-made default Scanner objects have been deprecated and will
+ be removed in a future revision. In their place are several new
+ global variable names that are now part of the publicly-supported
+ interface:
+
+ NEW NAME DEPRECATED NAME
+ -------- ----------------------------
+ CScanner SCons.Defaults.CScan
+ DSCanner SCons.Defaults.DScan
+ SourceFileScanner SCons.Defaults.ObjSourceScan
+ ProgramScanner SCons.Defaults.ProgScan
+
+ Of these, only ObjSourceScan was probably used at all, to add
+ new mappings of file suffixes to other scanners for use by the
+ Object() Builder. This should now be done as follows:
+
+ SourceFileScanner.add_scanner('.x', XScanner)
+
+ -- THE env.Copy() METHOD WILL CHANGE OR GO AWAY ENTIRELY
+
+ The env.Copy() method (to make a copy of a construction
+ environment) is being replaced by the env.Clone() method.
+
+ As of SCons 0.98, a deprecation warning has been added to
+ current uses of the env.Copy() method. At some point in
+ the future, the env.Copy() method will either be removed
+ entirely or have its behavior changed.
+
+ You can prepare for this by changing all your uses of env.Copy()
+ to env.Clone(), which has the exact same calling arguments.
+
+ NOTE: CHANGING USES OF env.Copy() TO env.Clone() WILL MAKE
+ YOUR SConscript FILES NOT WORK ON VERSIONS OF SCons BEFORE
+ 0.96.93.
+
+ If you change SConscript files in software that you make
+ available for download or otherwise distribute, other users
+ may try to build your software with an earlier version of
+ SCons that does not have the env.Clone() method. We recommend
+ preparing for this in one of two ways:
+
+ -- Make your SConscript files backwards-compatible by
+ including the following code near the beginning of your
+ top-level SConstruct file:
+
+ import SCons.Environment
+ try:
+ SCons.Environment.Environment.Clone
+ except AttributeError:
+ SCons.Environment.Environment.Clone = \
+ SCons.Environment.Environment.Copy
+
+ -- Use the EnsureSConsVersion() function to provide a
+ descriptive error message if your SConscript files
+ are executed by an earlier version of SCons:
+
+ EnsureSConsVersion(0, 96, 93)
+
+ -- THE CheckLib Configure TEST WILL CHANGE BEHAVIOR
+
+ The CheckLib() Configure test appends the lib(s) to the
+ Environment's LIBS list in 1.3 and earlier. In 1.3 there is a
+ new CheckLib argument, append, which defaults to True to
+ preserve the old behavior. In a future release, append will
+ be changed to default to False, to conform with autoconf and
+ user expectations, since it is usually used to build up
+ library lists in a right-to-left way.
- Of these, only ObjSourceScan was probably used at all, to add
- new mappings of file suffixes to other scanners for use by the
- Object() Builder. This should now be done as follows:
- SourceFileScanner.add_scanner('.x', XScanner)
SCons is developed with an extensive regression test suite, and a
rigorous development methodology for continually improving that suite.
Because of this, SCons is of sufficient quality that you can use it
- for real work. The "beta" status of the release reflects that we
- still may change interfaces in future releases, which may require
- modifications to your SConscript files. We strive to hold these
- changes to a minimum.
+ for real work.
- Nevertheless, please heed the following disclaimers:
+ The interfaces in release 1.0 will *not* be knowingly changed in
+ any new, future 1.x release. If an interface change should ever
+ become necessary due to extraordinary circumstances, the change
+ and an appropriate transition strategy will be documented in these
+ RELEASE notes.
+
+ As you use SCons, please heed the following:
- Please report any bugs or other problems that you find to our bug
tracker at our SourceForge project page:
would be more than glad to have your assistance in correcting this
problem... :-)
- In particular, the "SCons Design" documentation on the SCons web
- site is currently out of date, as we made significant changes to
- portions of the interface as we figured out what worked and what
- didn't during implementation.
+ - The "SCons Design" documentation on the SCons web site is very
+ out of date, as we made significant changes to portions of the
+ interface as we figured out what worked and what didn't during the
+ extensive beta implementation. The "SCons Design" document should
+ be used only for historical purposes, or for just an extremely
+ general understanding of SCons' architectural goals.
- There may be performance issues. Improving SCons performance
is an ongoing priority. If you still find the performance
KNOWN PROBLEMS IN THIS RELEASE:
- For a complete list of known problems, consult the SCons bug tracker
- page at SourceForge:
+ For a complete list of known problems, consult the SCons Issue Tracker
+ at tigris.org:
- http://sourceforge.net/tracker/?atid=398971&group_id=30337&func=browse
+ http://scons.tigris.org/project_issues.html
- Support for parallel builds (-j) does not work on WIN32 systems
prior to *official* Python release 2.2 (not 2.2 pre-releases).
use if you you want to fix your version of Python to support
parallel builds in SCons.
- - Again, the "SCons Design" documentation on the SCons web
- site is currently out of date. Take what you read there with a
- grain of salt.
+ - Again, the "SCons Design" documentation on the SCons web site is
+ out of date. Take what you read there with a grain of salt.
- On Win32 systems, you must put a space between the redirection
characters < and >, and the specified files (or construction
created as part of the build, and also does not clean up
SideEffect files (for example, Visual Studio .pdb files).
- - Switching content signatures from "MD5" to "timestamp" and back
- again can cause unusual errors. These errors can be cleared up by
- removing all .sconsign files.
-
- When using multiple Repositories, changing the name of an include
file can cause an old version of the file to be used.
- Unicode characters in path names do not work in all circumstances.
- - A stray source file in a BuildDir can prevent targets from being
- (re)built when they should.
-
- - SCons does not automatically rebuild LaTeX files when the file
- has an undefined reference on the first build.
-
- - Use of --implicit-cache with TargetSignatures('content') can,
- for some changes, not rebuild a file when necessary.
-
- SCons does not currently automatically check out SConstruct or
SConscript files from SCCS, RCS or BitKeeper.
With plenty of help from the SCons Development team:
Chad Austin
Charles Crain
+ Bill Deegan
Steve Leblanc
+ Greg Noel
Gary Oberbrunner
Anthony Roach
Greg Spencer
projects / scons.git / blobdiff