2 # __FILE__ __REVISION__ __DATE__ __DEVELOPER__
5 SCons - a software construction tool
10 This is a beta release of SCons, a tool for building software (and other
11 files). SCons is implemented in Python, and its "configuration files"
12 are actually Python scripts, allowing you to use the full power of a
13 real scripting language to solve build problems. You do not, however,
14 need to know Python to use SCons effectively.
16 So that everyone using SCons can help each other learn how to use it
17 more effectively, please sign up for the scons-users mailing list at:
19 http://lists.sourceforge.net/lists/listinfo/scons-users
25 This is a pre-release for testing the eighth beta release of SCons.
26 Please consult the CHANGES.txt file for a list of specific changes
29 Please note the following important changes since release 0.96:
31 - The ParseConfig() method now adds library file names returned
32 by the specified *-config command to the $LIBS construction
33 variable, instead of returning them (the same way it handles
36 - When compiling with Microsoft Visual Studio, SCons no longer
37 adds the ATL and MFC directories to the INCLUDE and LIB
38 environment variables by default. If you want these directories
39 included in your environment variables, you should now set the
40 $MSVS_USE_MFC_DIRS *construction* variable when initializing
43 env = Environment(MSVS_USE_MFC_DIRS = 1)
45 - The following deprecated global functions have been removed:
46 ParseConfig(), SetBuildSignatureType(), SetContentSignatureType(),
47 SetJobs() and GetJobs().
49 - The deprecated "validater" keyword to the Options.Add() method
52 Please note the following important changes since release 0.95:
54 - All Builder calls (both built-in like Program(), Library(),
55 etc. and customer Builders) now always return a list of target
56 Nodes. If the Builder only builds one target, the Builder
57 call will now return a list containing that target Node, not
58 the target Node itself as it used to do.
60 This change should be invisibile to most normal uses of the
61 return values from Builder calls. It will cause an error if the
62 SConscript file was performing some direct manipulation of the
63 returned Node value. For example, an attempt to print the name
64 of a target returned by the Object() Builder:
66 target = Object('foo.c')
70 Will now need to access the first element in the list returned by
73 target = Object('foo.c')
77 This change was introduced to make the data type returned by Builder
78 calls consistent (always a list), regardless of platform or number
81 - The SConsignFile() function now uses an internally-supplied
82 SCons.dblite module as the default DB scheme for the .sconsign file.
83 If you are using the SConsignFile() function without an explicitly
84 specified dbm_module argument, this will cause all of your targets
85 to be recompiled the first time you use SCons 0.96. To preserve the
86 previous behavior, specify the "anydbm" module explicitly:
89 SConsignFile('.sconsign_file_name', anydbm)
91 - The internal format of .sconsign files has been changed. This might
92 cause warnings about "ignoring corrupt .sconsign files" and rebuilds
93 when you use SCons 0.96 for the first time in a tree that was
94 previously built with SCons 0.95 or earlier.
96 - The scan_check function that can be supplied to a custom Scanner now
97 must take two arguments, the Node to be checked and a construction
98 environment. It previously only used the Node as an argument.
100 - The internal Scanner.add_skey() method no longer works for the
101 default scanners, which now use construction variables to hold their
102 lists of suffixes. If you had a custom Tool specification that was
103 reaching into the internals in this way to add a suffix to one of
104 the following scanner, you must now add the suffix to a construction
105 environment through which you plan to call the scanner, as follows:
107 CScan.add_skey('.x') => env.Append(CPPSUFFIXES = ['.x'])
108 DScan.add_skey('.x') => env.Append(DSUFFIXES = ['.x'])
109 FortranScan.add_skey('.x') => env.Append(FORTRANSUFFIXES = ['.x'])
111 - The "node_factory" and "scanner" keyword arguments to the Builder()
112 function have been removed. In their place, the separate and more
113 flexible "target_factory," "source_factory," "target_scanner" and
114 "source scanner" keywords should be used instead.
116 - SCons now treats file "extensions" that contain all digits (for
117 example, "file.123") as part of the file basename, for easier
118 handling of version numbers in the names of shared libraries
119 and other files. Builders will now add their file extensions to
120 file names specified with all-digit extensions. If you need to
121 generate a file with an all-digit extension using a Builder that
122 adds a file extension, you can preserve the previous behavior by
123 wrapping the file name in a File() call.
125 - The behavior of the env.Append() and env.Prepend() methods has
126 changed when appending a string value to a UserList, or vice versa.
127 They now behave like normal Python addition of a string to
128 a UserList. Given an initialization and an env.Append() call like:
130 env = Environment(VAR1=UserList(['foo']), VAR2='foo')
131 env.Append(VAR1='bar', VAR2=UserList(['bar'])
133 The resulting values of $VAR1 and $VAR2 will now be ['foo', 'b',
134 'a', 'r'] and ['f', 'o', 'o', 'bar'], respectively. This is because
135 Python UserList objects treat strings as sequences of letters when
136 adding them to the value of the UserList.
138 The old behavior of yielding $VAR1 and $VAR2 values of ['foo',
139 'bar'] when either variable is a UserList object now requires that
140 the string variables be enclosed in a list:
142 env = Environment(VAR1=UserList(['foo']), VAR2=['foo'])
143 env.Append(VAR1='bar', VAR2=UserList(['bar']))
145 Note that the SCons behavior when appending to normal lists has
146 *not* changed, and the behavior of all of the default values that
147 SCons uses to initialize all construction variables has *not*
148 changed. This change *only* affects any cases where you explicitly
149 use UserList objects to initialize or append to a variable.
151 SCons is developed with an extensive regression test suite, and a
152 rigorous development methodology for continually improving that suite.
153 Because of this, SCons is of sufficient quality that you can use it
154 for real work. The "beta" status of the release reflects that we
155 still may change interfaces in future releases, which may require
156 modifications to your SConscript files. We strive to hold these
157 changes to a minimum.
159 Nevertheless, please heed the following disclaimers:
161 - Please report any bugs or other problems that you find to our bug
162 tracker at our SourceForge project page:
164 http://sourceforge.net/tracker/?func=add&group_id=30337&atid=398971
166 We have a reliable bug-fixing methodology already in place and
167 strive to respond to problems relatively quickly.
169 - Documentation is spottier than we'd like. You may need to dive
170 into the source code to figure out how to do something. Asking
171 questions on the scons-users mailing list is also welcome. We
172 will be addressing the documentation in upcoming releases, but
173 would be more than glad to have your assistance in correcting this
176 In particular, the "SCons Design" documentation on the SCons web
177 site is currently out of date, as we made significant changes to
178 portions of the interface as we figured out what worked and what
179 didn't during implementation.
181 - There may be performance issues. Improving SCons performance
182 is an ongoing priority. If you still find the performance
183 unacceptable, we would very much like to hear from you and learn
184 more about your configuration so we can optimize the right things.
186 - Error messages don't always exist where they'd be helpful.
187 Please let us know about any errors you ran into that would
188 have benefitted from a (more) descriptive message.
190 KNOWN PROBLEMS IN THIS RELEASE:
192 For a complete list of known problems, consult the SCons bug tracker
195 http://sourceforge.net/tracker/?atid=398971&group_id=30337&func=browse
197 - Support for parallel builds (-j) does not work on WIN32 systems
198 prior to *official* Python release 2.2 (not 2.2 pre-releases).
200 Prior to Python 2.2, there is a bug in Python's Win32
201 implementation such that when a thread spawns an external command,
202 it blocks all threads from running. This breaks the SCons
203 multithreading architecture used to support -j builds.
205 We have included a patch file, os_spawnv_fix.diff, that you can
206 use if you you want to fix your version of Python to support
207 parallel builds in SCons.
209 - Again, the "SCons Design" documentation on the SCons web
210 site is currently out of date. Take what you read there with a
213 - On Win32 systems, you must put a space between the redirection
214 characters < and >, and the specified files (or construction
215 variable expansions):
217 command < $SOURCE > $TARGET
219 If you don't supply a space (for example, "<$SOURCE"), SCons will
220 not recognize the redirection.
222 - MSVC .res files are not rebuilt when icons change.
224 - The -c option does not clean up .sconsign files or directories
225 created as part of the build, and also does not clean up
226 SideEffect files (for example, Visual Studio .pdb files).
228 - Switching content signatures from "MD5" to "timestamp" and back
229 again can cause unusual errors. These errors can be cleared up by
230 removing all .sconsign files.
232 - When using multiple Repositories, changing the name of an include
233 file can cause an old version of the file to be used.
235 - There is currently no way to force use of a relative path (../*)
236 for directories outside the top-level SConstruct file.
238 - The Jar() Builder will, on its second or subsequent invocation,
239 package up the .sconsign files that SCons uses to track signatures.
240 You can work around this by using the SConsignFile() function
241 to collect all of the .sconsign information into a single file
242 outside of the directory being packaged by Jar().
244 - SCons does not currently have a way to detect that an intermediate
245 file has been corrupted from outside and should be rebuilt.
247 - Unicode characters in path names do not work in all circumstances.
249 - A stray source file in a BuildDir can prevent targets from being
250 (re)built when they should.
252 - SCons does not automatically rebuild LaTeX files when the file
253 has an undefined reference on the first build.
255 - Use of --implicit-cache with TargetSignatures('content') can,
256 for some changes, not rebuild a file when necessary.
258 - SCons does not currently automatically check out SConstruct or
259 SConscript files from SCCS, RCS or BitKeeper.
261 - No support yet for the following planned command-line options:
263 -d -e -l --list-actions --list-derived --list-where
264 -o --override -p -r -R -w --write-filenames
265 -W --warn-undefined-variables
269 Thank you for your interest, and please let us know how we can help
270 improve SCons for your needs.
273 knight at baldmt dot com
274 http://www.baldmt.com/~knight/
276 With plenty of help from the SCons Development team: