1 # Copyright (c) 2001, 2002 Steven Knight
2 # __FILE__ __REVISION__ __DATE__ __DEVELOPER__
5 SCons - a software construction tool
13 From Derrick 'dman' Hudson:
15 - Support Repositories on other file systems by symlinking or
16 copying files when hard linking won't work.
20 - Remove Python bytecode (*.pyc) files from the scons-local packages.
22 - Have FunctionActions print a description of what they're doing
23 (a representation of the Python call).
25 - Fix the Install() method so that, like other actions, it prints
26 what would have happened when the -n option is used.
28 - Don't create duplicate source files in a BuildDir when the -n
31 - Refactor the Scanner interface to eliminate unnecessary Scanner
32 calls and make it easier to write efficient scanners.
34 - Added a "recursive" flag to Scanner creation that specifies the
35 Scanner should be invoked recursively on dependency files returned
38 - Significant performance improvement from using a more efficient
39 check, throughout the code, for whether a Node has a Builder.
41 - Fix specifying only the source file to MultiStepBuilders such as
42 the Program Builder. (Bug reported by Dean Bair.)
44 - Fix an exception when building from a file with the same basename as
45 the subdirectory in which it lives. (Bug reported by Gerard Patel.)
47 - Fix automatic deduction of a target file name when there are
48 multiple source files specified; the target is now deduced from just
49 the first source file in the list.
51 - Documentation fixes: better initial explanation of SConscript files;
52 fix a misformatted "table" in the StaticObject explanation.
54 From Steven Knight and Steve Leblanc:
56 - Fix the -c option so it will remove symlinks.
60 - Add a Clean() method to support removing user-specified targets
61 when using the -c option.
63 - Add a development script for running SCons through PyChecker.
65 - Clean up things found by PyChecker (mostly unnecessary imports).
67 - Add a script to use HappyDoc to create HTML class documentation.
71 - Make the Environment.get() method return None by default.
75 - Add SetJobs() and GetJobs() methods to allow configuration of the
76 number of default jobs (still overridden by -j).
78 - Convert the .sconsign file format from ASCII to a pickled Python
81 - Error message cleanups: Made consistent the format of error
82 messages (now all start with "scons: ***") and warning messages (now
83 all start with "scons: warning:"). Caught more cases with the "Do
84 not know how to build" error message.
86 - Added support for the MinGW tool chain.
88 - Added a --debug=inclues option.
92 RELEASE 0.09 - Thu, 5 Dec 2002 04:48:25 -0600
96 - Add a Prepend() method to Environments, to append values to
97 the beginning of construction variables.
101 - Add long command-line support to the "lib" Tool (Microsoft library
106 - Allow $$ in a string to be passed through as $.
108 - Support file names with odd characters in them.
110 - Add support for construction variable substition on scanner
111 directories (in CPPPATH, F77PATH, LIBPATH, etc.).
113 From Charles Crain and Steven Knight:
115 - Add Repository() functionality, including the -Y option.
119 - Fix auto-deduction of target names so that deduced targets end
120 up in the same subdirectory as the source.
122 - Don't remove source files specified on the command line!
124 - Suport the Intel Fortran Compiler (ifl.exe).
126 - Supply an error message if there are no command-line or
127 Default() targets specified.
129 - Fix the ASPPCOM values for the GNU assembler.
130 (Bug reported by Brett Polivka.)
132 - Fix an exception thrown when a Default() directory was specified
133 when using the -U option.
135 - Issue a warning when -c can't remove a target.
137 - Eliminate unnecessary Scanner calls by checking for the
138 existence of a file before scanning it. (This adds a generic
139 hook to check an arbitrary condition before scanning.)
141 - Add explicit messages to tell when we're "Reading SConscript files
142 ...," "done reading SConscript files," "Building targets," and
143 "done building targets." Add a -Q option to supress these.
145 - Add separate $SHOBJPREFIX and $SHOBJSUFFIX construction variables
146 (by default, the same as $OBJPREFIX and $OBJSUFFIX).
148 - Add Make-like error messages when asked to build a source file,
149 and before trying to build a file that doesn't have all its source
150 files (including when an invalid drive letter is used on WIN32).
152 - Add an scons-local-{version} package (in both .tar.gz and .zip
153 flavors) to help people who want to ship SCons as a stand-alone
154 build tool in their software packages.
156 - Prevent SCons from unlinking files in certain situations when
157 the -n option is used.
159 - Change the name of Tool/lib.py to Tool/mslib.py.
161 From Steven Knight and Anthony Roach:
163 - Man page: document the fact that Builder calls return Node objects.
167 - Refactor option processing to use our own version of Greg Ward's
168 Optik module, modified to run under Python 1.5.2.
170 - Add a ParseConfig() command to modify an environment based on
171 parsing output from a *-config command.
175 - Fix interpretation of '#/../foo' on Win32 systems.
179 - Fixed use of command lines with spaces in their arguments,
180 and use of Nodes with spaces in their string representation.
182 - Make access and modification times of files in a BuildDir match
183 the source file, even when hard linking isn't available.
185 - Make -U be case insensitive on Win32 systems.
187 - Issue a warning and continue when finding a corrupt .sconsign file.
189 - Fix using an alias as a dependency of a target so that if one of the
190 alias' dependencies gets rebuilt, the resulting target will, too.
192 - Fix differently ordered targets causing unnecessary rebuilds
193 on case insensitive systems.
195 - Use os.system() to execute external commands whenever the "env"
196 utility is available, which is much faster than fork()/exec(),
197 and fixes the -j option on several platforms.
199 - Fix use of -j with multiple targets.
201 - Add an Options() object for friendlier accomodation of command-
204 - Add support for Microsoft VC++ precompiled header (.pch) files,
205 debugger (.pdb) files, and resource (.rc) files.
207 - Don't compute the $_CPPINCFLAGS, $_F77INCFLAGS, $_LIBFLAGS and
208 $_LIBDIRFLAGS variables each time a command is executed, define
209 them so they're computed only as needed. Add a new _concat
210 function to the Environment that allows people to define their
211 own similar variables.
213 - Fix dependency scans when $LIBS is overridden.
215 - Add EnsurePythonVersion() and EnsureSConsVersion() functions.
217 - Fix the overly-verbose stack trace on ListBuilder build errors.
219 - Add a SetContentSignatureType() function, allowing use of file
220 timestamps instead of MD5 signatures.
222 - Make -U and Default('source') fail gracefully.
224 - Allow the File() and Dir() methods to take a path-name string as
225 the starting directory, in addition to a Dir object.
227 - Allow the command handler to be selected via the SPAWN, SHELL
228 and ESCAPE construction variables.
230 - Allow construction variables to be overridden when a Builder
235 - Dynamically check for the existence of utilities with which to
236 initialize Environments by default.
240 RELEASE 0.08 - Mon, 15 Jul 2002 12:08:51 -0500
244 - Fixed a bug with relative CPPPATH dirs when using BuildDir().
245 (Bug reported by Bob Summerwill.)
247 - Added a warnings framework and a --warn option to enable or
250 - Make the C scanner warn users if files referenced by #include
251 directives cannot be found and --warn=dependency is specified.
253 - The BUILDERS construction variable should now be a dictionary
254 that maps builder names to actions. Existing uses of lists,
255 and the Builder name= keyword argument, generate warnings
256 about use of deprecated features.
258 - Removed the "shared" keyword argument from the Object and
261 - Added separated StaticObject, SharedObject, StaticLibrary and
262 SharedLibrary builders. Made Object and Library synonyms for
263 StaticObject and StaticLibrary, respectively.
265 - Add LIBS and LIBPATH dependencies for shared libraries.
267 - Removed support for the prefix, suffix and src_suffix arguments
268 to Builder() to be callable functions.
270 - Fix handling file names with multiple dots.
272 - Allow a build directory to be outside of the SConstruct tree.
274 - Add a FindFile() function that searches for a file node with a
277 - Add $CPPFLAGS to the shared-object command lines for g++ and gcc.
279 From Charles Crain and Steven Knight:
281 - Add a "tools=" keyword argument to Environment instantiation,
282 and a separate Tools() method, for more flexible specification
283 of tool-specific environment changes.
287 - Add a "platform=" keyword argument to Environment instantiation,
288 and a separate Platform() method, for more flexible specification
289 of platform-specific environment changes.
291 - Updated README instructions and setup.py code to catch an
292 installation failure from not having distutils installed.
294 - Add descriptions to the -H help text for -D, -u and -U so
295 people can tell them apart.
297 - Remove the old feature of automatically splitting strings
298 of file names on white space.
300 - Add a dependency Scanner for native Fortran "include" statements,
301 using a new "F77PATH" construction variable.
303 - Fix C #include scanning to detect file names with characters like
306 - Add more specific version / build output to the -v option.
308 - Add support for the GNU as, Microsoft masm, and nasm assemblers.
310 - Allow the "target" argument to a Builder call to be omitted, in
311 which case the target(s) are deduced from the source file(s) and the
312 Builder's specified suffix.
314 - Add a tar archive builder.
316 - Add preliminary support for the OS/2 Platform, including the icc
321 - Fix --implicit-cache if the scanner returns an empty list.
325 - Add a "multi" keyword argument to Builder creation that specifies
326 it's okay to call the builder multiple times for a target.
328 - Set a "multi" on Aliases so multiple calls will append to an Alias.
330 - Fix emitter functions' use of path names when using BuildDir or
333 - Fix --implicit-cache causing redundant rebuilds when the header
336 - Fix --implicit-cache when a file has no implicit dependencies and
337 its source is generated.
339 - Make the drive letters on Windows always be the same case, so that
340 changes in the case of drive letters don't cause a rebuild.
342 - Fall back to importing the SCons.TimeStamp module if the SCons.MD5
343 module can't be imported.
345 - Fix interrupt handling to guarantee that a single interrupt will
346 halt SCons both when using -j and not.
348 - Fix .sconsign signature storage so that output files of one build
349 can be safely used as input files to another build.
351 - Added a --debug=time option to print SCons execution times.
353 - Print an error message if a file can't be unlinked before being
354 built, rather than just silently terminating the build.
356 - Add a SideEffect() method that can be used to tell the build
357 engine that a given file is created as a side effect of building
358 a target. A file can be specified as a side effect of more than
359 one build comand, in which case the commands will not be executed
362 - Significant performance gains from not using our own version of
363 the inefficient stock os.path.splitext() method, caching source
364 suffix computation, code cleanup in MultiStepBuilder.__call__(),
365 and replicating some logic in scons_subst().
367 - Add --implicit-deps-changed and --implicit-deps-unchanged options.
369 - Add a GetLaunchDir() function.
371 - Add a SetBuildSignatureType() function.
375 - Add an Append() method to Environments, to append values to
376 construction variables.
378 - Change the name of Update() to Replace(). Keep Update() as a
379 deprecated synonym, at least for now.
383 - Use a $PYTHON construction variable, initialized to sys.executable,
384 when using Python to build parts of the SCons packages.
386 - Use sys.prefix, not sys.exec_prefix, to find pdb.py.
390 RELEASE 0.07 - Thu, 2 May 2002 13:37:16 -0500
394 - Changes to build SCons packages on IRIX (and other *NIces).
396 - Don't create a directory Node when a file already exists there,
399 - Add 'dirs' and 'names' keyword arguments to SConscript for
400 easier specification of subsidiary SConscript files.
404 - Internal cleanup of environment passing to function Actions.
406 - Builders can now take arbitrary keyword arguments to create
407 attributes to be passed to: command generator functions,
408 FunctionAction functions, Builder emitter functions (below),
409 and prefix/suffix generator functions (below).
411 - Command generator functions can now return ANYTHING that can be
412 converted into an Action (a function, a string, a CommandGenerator
413 instance, even an ActionBase instance).
415 - Actions now call get_contents() with the actual target and source
416 nodes used for the build.
418 - A new DictCmdGenerator class replaces CompositeBuilder to support
419 more flexible Builder behavior internally.
421 - Builders can now take an emitter= keyword argument. An emitter
422 is a function that takes target, source, and env argument, then
423 return a 2-tuple of (new sources, new targets). The emitter is
424 called when the Builder is __call__'ed, allowing a user to modify
425 source and target lists.
427 - The prefix, suffix and src_suffix Builder arguments now take a
428 callable as well a string. The callable is passed the Environment
429 and any extra Builder keyword arguments and is expected to return
430 the appropriate prefix or suffix.
432 - CommandActions can now be a string, a list of command + argument
433 strings, or a list of commands (strings or lists).
435 - Added shared library support. The Object and Library Builders now
436 take a "shared=1" keyword argument to specify that a shared object
437 or shared library should be built. It is an error to try to build
438 static objects into a shared library or vice versa.
440 - Win32 support for .def files has been added. Added the Win32-specific
441 construction variables $WIN32DEFPREFIX, $WIN32DEFSUFFIX,
442 $WIN32DLLPREFIX and $WIN32IMPLIBPREFIX. When building a .dll,
443 the new construction variable $WIN32_INSERT_DEF, controls whether
444 the appropriately-named .def file is inserted into the target
445 list (if not already present). A .lib file is always added to
446 a Library build if not present in the list of targets.
448 - ListBuilder now passes all targets to the action, not just the first.
450 - Fix so that -c now deletes generated yacc .h files.
452 - Builder actions and emitter functions can now be initialized, through
453 construction variables, to things other than strings.
455 - Make top-relative '#/dir' lookups work like '#dir'.
457 - Fix for relative CPPPATH directories in subsidiary SConscript files
460 - Add a for_signature argument to command generators, so that
461 generators that need to can return distinct values for the
462 command signature and for executing the command.
466 - Create a better scons.bat file from a py2bat.py script on the Python
467 mailing list two years ago (modeled after pl2bat.pl).
471 - Fix so that -c -n does *not* remove the targets!
473 - Man page: Add a hierarchical libraries + Program example.
475 - Support long MSVC linker command lines through a builder action
476 that writes to a temporary file and uses the magic MSVC "link @file"
477 argument syntax if the line is longer than 2K characters.
479 - Fix F77 command-line options on Win32 (use /Fo instead of -o).
481 - Use the same action to build from .c (lower case) and .C (upper
482 case) files on case-insensitive systems like Win32.
484 - Support building a PDF file directly from a TeX or LaTeX file
485 using pdftex or pdflatex.
487 - Add a -x option to runtest.py to specify the script being tested.
488 A -X option indicates it's an executable, not a script to feed
489 to the Python interpreter.
491 - Add a Split() function (identical to SCons.Util.argmunge()) for use
492 in the next release, when Builders will no longer automatically split
493 strings on white space.
497 - Add the SConscriptChdir() method.
501 - Fix --debug=tree when used with directory targets.
503 - Significant internal restructuring of Scanners and Taskmaster.
505 - Added new --debug=dtree option.
507 - Fixes for --profile option.
509 - Performance improvement in construction variable substitution.
511 - Implemented caching of content signatures, plus added --max-drift
512 option to control caching.
514 - Implemented caching of dependency signatures, enabled by new
515 --implicit-cache option.
517 - Added abspath construction variable modifier.
519 - Added $SOURCE variable as a synonym for $SOURCES[0].
521 - Write out .sconsign files on error or interrupt so intermediate
522 build results are saved.
524 - Change the -U option to -D. Make a new -U that builds just the
525 targets from the local SConscript file.
527 - Fixed use of sys.path so Python modules can be imported from
528 the SConscript directory.
530 - Fix for using Aliases with the -u, -U and -D options.
532 - Fix so that Nodes can be passed to SConscript files.
536 - Changes for official Debian packaging.
540 RELEASE 0.06 - Thu, 28 Mar 2002 01:24:29 -0600
544 - Fix command generators to expand construction variables.
546 - Make FunctionAction arguments be Nodes, not strings.
548 From Stephen Kennedy:
550 - Performance: Use a dictionary, not a list, for a Node's parents.
554 - Add .zip files to the packages we build.
556 - Man page: document LIBS, fix a typo, document ARGUMENTS.
558 - Added RANLIB and RANLIBFLAGS construction variables. Only use them
559 in ARCOM if there's a "ranlib" program on the system.
561 - Add a configurable CFILESUFFIX for the Builder of .l and .y files
564 - Add a CXXFile Builder that turns .ll and .yy files into .cc files
565 (configurable via a CXXFILESUFFIX construction variable).
567 - Use the POSIX-standard lex -t flag, not the GNU-specific -o flag.
568 (Bug reported by Russell Christensen.)
570 - Fixed an exception when CPPPATH or LIBPATH is a null string.
571 (Bug reported by Richard Kiss.)
573 - Add a --profile=FILE option to make profiling SCons easier.
575 - Modify the new DVI builder to create .dvi files from LaTeX (.ltx
578 - Add support for Aliases (phony targets).
580 - Add a WhereIs() method for searching for path names to executables.
582 - Add PDF and PostScript document builders.
584 - Add support for compiling Fortran programs from a variety of
585 suffixes (a la GNU Make): .f, .F, .for, .FOR, .fpp and .FPP
587 - Support a CPPFLAGS variable on all default commands that use the
592 - Add support for the -U option.
594 - Allow CPPPATH, LIBPATH and LIBS to be specified as white-space
597 - Add a document builder to create .dvi files from TeX (.tex) files.
601 - Fix: Construction variables with values of 0 were incorrectly
604 - Support env['VAR'] to fetch construction variable values.
606 - Man page: document Precious().
610 RELEASE 0.05 - Thu, 21 Feb 2002 16:50:03 -0600
614 - Set PROGSUFFIX to .exe under Cygwin.
618 - Allow a library to specified as a command-line source file, not just
619 in the LIBS construction variable.
621 - Compensate for a bug in os.path.normpath() that returns '' for './'
624 - More performance optimizations: cache #include lines from files,
625 eliminate unnecessary calls.
627 - If a prefix or suffix contains white space, treat the resulting
628 concatenation as separate arguments.
630 - Fix irregularities in the way we fetch DevStudio information from
631 the Windows registry, and in our registry error handling.
635 - Flush stdout after print so it intermixes correctly with stderr
638 - Allow Scanners to return a list of strings, and document how to
639 write your own Scanners.
641 - Look up implicit (scanned) dependencies relative to the directory
642 of file being scanned.
644 - Make writing .sconsign files more robust by first trying to write
645 to a temp file that gets renamed.
647 - Create all of the directories for a list of targets before trying
648 to build any of the targets.
650 - WIN32 portability fixes in tests.
652 - Allow the list of variables exported to an SConscript file to be
655 - Document the overlooked LIBPATH construction variable.
656 (Bug reported by Eicke Godehardt.)
658 - Fix so that Ignore() ignores indirect, implicit dependencies
659 (included files), not just direct dependencies.
661 - Put the man page in the Debian distribution.
663 - Run HTML docs through tidy to clean up the HTML (for Konqueror).
665 - Add preliminary support for Unicode strings.
667 - Efficiency: don't scan dependencies more than once during the
670 - Fix the -c option so it doesn't stop removing targets if one doesn't
672 (Bug reported by Paul Connell.)
674 - Fix the --debug=pdb option when run on Windows NT.
675 (Bug reported by Paul Connell.)
677 - Add support for the -q option.
681 - Add support for the -u option.
683 - Add .cc and .hh file suffixes to the C Scanner.
687 - Make the scons script return an error code on failures.
689 - Add support for using code to generate a command to build a target.
693 RELEASE 0.04 - Wed, 30 Jan 2002 11:09:42 -0600
697 - Significant performance improvements in the Node.FS and
700 - Fix signatures of binary files on Win32 systems.
702 - Allow LIBS and LIBPATH to be strings, not just arrays.
704 - Print a traceback if a Python-function builder throws an exception.
708 - Fix using a directory as a Default(), and allow Default() to
709 support white space in file names for strings in arrays.
711 - Man page updates: corrected some mistakes, documented various
712 missing Environment methods, alphabetized the construction
713 variables and other functions, defined begin and end macros for
714 the example sections, regularized white space separation, fixed
715 the use of Export() in the Multiple Variants example.
717 - Function action fixes: None is now a successful return value.
718 Exceptions are now reported. Document function actions.
720 - Add 'Action' and 'Scanner' to the global keywords so SConscript
721 files can use them too.
723 - Removed the Wrapper class between Nodes and Walkers.
725 - Add examples using Library, LIBS, and LIBPATH.
727 - The C Scanner now always returns a sorted list of dependencies
728 so order changes don't cause unnecessary rebuilds.
730 - Strip $(-$) bracketed text from command lines. Use this to
731 surround $_INCDIRS and $_LIBDIRS so we don't rebuild in response
732 to changes to -I or -L options.
734 - Add the Ignore() method to ignore dependencies.
736 - Provide an error message when a nonexistent target is specified
739 - Remove targets before building them, and add an Environment
740 Precious() method to override that.
742 - Eliminate redundant calls to the same builder when the target is a
743 list of targets: Add a ListBuilder class that wraps Builders to
744 handle lists atomically. Extend the Task class to support building
745 and updating multiple targets in a single Task. Simplify the
746 interface between Task and Taskmaster.
748 - Add a --debug=pdb option to re-run SCons under the Python debugger.
750 - Only compute a build signature once for each node.
752 - Changes to our sys.path[] manipulation to support installation into
753 an arbitrary --prefix value.
757 - Add var=value command-line arguments.
761 RELEASE 0.03 - Fri, 11 Jan 2002 01:09:30 -0600
765 - Performance improvements in the Node.FS and Sig.Calculator classes.
767 - Add the InstallAs() method.
769 - Execute commands through an external interpreter (sh, cmd.exe, or
770 command.com) to handle redirection metacharacters.
772 - Allow the user to supply a command handler.
776 - Search both /usr/lib and /usr/local/lib for scons directories by
777 adding them both to sys.path, with whichever is in sys.prefix first.
779 - Fix interpreting strings of multiple white-space separated file names
780 as separate file names, allowing prefixes and suffixes to be appended
781 to each individually.
783 - Refactor to move CompositeBuilder initialization logic from the
784 factory wrapper to the __init__() method, and allow a Builder to
785 have both an action and a src_builder (or array of them).
787 - Refactor BuilderBase.__call__() to separate Node creation/lookup
788 from initialization of the Node's builder information.
790 - Add a CFile Builder object that supports turning lex (.l) and
791 yacc (.y) files into .c files.
793 - Document: variable interpretation attributes; how to propogate
794 the user's environment variables to executed commands; how to
795 build variants in multiple BuildDirs.
797 - Collect String, Dict, and List type-checking in common utility
798 routines so we can accept User{String,Dict,List}s all over.
800 - Put the Action factory and classes into their own module.
802 - Use one CPlusPlusAction in the Object Builder's action dictionary,
803 instead of letting it create multiple identical instances.
805 - Document the Install() and InstallAs() methods.
809 - Require that a Builder be given a name argument, supplying a
810 useful error message when it isn't.
814 - Add a "duplicate" keyword argument to BuildDir() that can be set
815 to prevent linking/copying source files into build directories.
817 - Add a "--debug=tree" option to print an ASCII dependency tree.
819 - Fetch the location of the Microsoft Visual C++ compiler(s) from
820 the Registry, instead of hard-coding the location.
822 - Made Scanner objects take Nodes, not path names.
824 - Have the C Scanner cache the #include file names instead of
825 (re-)scanning the file each time it's called.
827 - Created a separate class for parent "nodes" of file system roots,
828 eliminating the need for separate is-parent-null checks everywhere.
830 - Removed defined __hash__() and __cmp() methods from FS.Entry, in
831 favor of Python's more efficient built-in identity comparisons.
835 RELEASE 0.02 - Sun, 23 Dec 2001 19:05:09 -0600
839 - Added the Install(), BuildDir(), and Export() methods.
841 - Fix the -C option by delaying setting the top of the FS tree.
843 - Avoid putting the directory path on the libraries in the LIBS
844 construction variable.
846 - Added a GetBuildPath() method to return the full path to the
847 Node for a specified string.
849 - Fixed variable substitution in CPPPATH and LIBPATH.
853 - Fixed the version comment in the scons.bat (the UNIX geek used
856 - Fix to setup.py so it doesn't require a sys.argv[1] argument.
858 - Provide make-like warning message for "command not found" and
861 - Added an EXAMPLES section to the man page.
863 - Make Default() targets properly relative to their SConscript
868 - Documented CXXFLAGS, CXXCOM, and CPPPATH.
870 - Fixed SCONS_LIB_DIR to work as documented.
872 - Made Default() accept Nodes as arguments.
874 - Changed Export() to make it easier to use.
876 - Added the Import() and Return() methods.
880 RELEASE 0.01 - Thu Dec 13 19:25:23 CST 2001
882 A brief overview of important functionality available in release 0.01:
884 - C and C++ compilation on POSIX and Windows NT.
886 - Automatic scanning of C/C++ source files for #include dependencies.
888 - Support for building libraries; setting construction variables
889 allows creation of shared libraries.
891 - Library and C preprocessor search paths.
893 - File changes detected using MD5 signatures.
895 - User-definable Builder objects for building files.
897 - User-definable Scanner objects for scanning for dependencies.
899 - Parallel build (-j) support.
901 - Dependency cycles detected.
903 - Linux packages available in RPM and Debian format.
905 - Windows installer available.