[CMake] Buggy CPack generator behaviour?

[Bjørn Forsman]

2011/7/27 Eric Noulard <eric.noulard at gmail.com>:
> 2011/7/27 Bjørn Forsman <bjorn.forsman at gmail.com>:
>> Hi all,
>>
>> I wonder if I've hit some bugs in the CPack generators, specifically
>> TGZ and DEB. They do not behave as I expect them to. What I expect
>> them to do is to generate an archive of files that look exactly like
>> what 'make install' puts in DESTDIR. If this is a wrong assumption
>> then please tell me.
>
> This is a wrong assumption for several reasons but keep reading.
>
> I'll try to answer inline, for the part I do have answer :-]
>
>> So based on that assumption, here are the issues:
>>
>> 1. TGZ doesn't populate the archive with all needed parent
>> directories. A binary that 'make install' puts in
>> DESTDIR/usr/local/bin is put in <archive_root>/bin with TGZ. I would
>> have expected the archive to contain <archive_root>/usr/local/bin
>> (like the DEB generator does). Is there maybe a configuration option
>> for this?
>
> CPack does not use CMAKE_INSTALL_PREFIX but
>
> CPACK_PACKAGING_INSTALL_PREFIX
>
> if this variable is not defined, each CPack generator has
> an historical builtin value which is used.
>
> ArchiveGenerator (TGZ, ZIP, TBZ2 etc...) are using none
> RPM has /usr
> DEB has /usr
>
> if you do
>
> cpack -D CPACK_PACKAGING_INSTALL_PREFIX=/usr/local -G TGZ
> then you may get the wanted prefix in TGZ.
>
>> 2. TGZ fails on absolute DESTINATION paths:
>>  CMake Error at /home/bjornfor/eraseme/build/cmake_install.cmake:44 (FILE):
>>    file INSTALL cannot copy file "/home/bjornfor/eraseme/build/hello" to
>>    "/usr/bin/hello".
>
> I see you point.
> TGZ may handle absolute install path if you set(CPACK_SET_DESTDIR ON)
>
> i.e.
> cpack -D CPACK_SET_DESTDIR=ON -G TGZ will make TGZ tolerate absolute
> install path.
>
>> (And no, I don't want to run as root just to create an archive. If DEB
>> can handle this so should TGZ.)
>
> DEB (and RPM) internally set CPACK_SET_DESTDIR to ON (in fact I_ON)
> This is not the default behavior for archive generators mainly for
> backward-compatibility reason,
> and other reason I cannot remember but you should find a lengthly
> discussion about that
> on some closed bug on the bug tracker.
>
> I may dig this if you want the precise ref.
>
>> 3. DEB won't generate a .deb with binaries in /usr/local/bin. Example:
>> set CMAKE_INSTALL_PREFIX=/usr/local and install(TARGETS hello
>> DESTINATION bin). 'make install' puts hello in /usr/local/bin but the
>> .deb contains /usr/bin/hello (missing 'local').
>
> Same as 1)
>
> use CPACK_PACKAGING_INSTALL_PREFIX, this is a feature not a bug.
>
>> Maybe the last issue is by design because no packaged software should
>> install to /usr/local. But wouldn't it be nicer if cpack either (1)
>> tell users that it changed some paths, (2) error out and die or (3) be
>> "stupid" and allow it?
>>
>> Can anyone help me with this? Or better yet, fix it? :-)
>
> I agree that some CPack generators behavior discrepancies are puzzling at first
> but making it more coherent is difficult without breaking backward
> compatibility.
>
> Unless I'm wrong there is nothing to fix here but the CPack documentation,
> for which patches are welcome as well.
>
> See the discussion here:
> http://public.kitware.com/Bug/view.php?id=10067
>
> And the may be sparse but existing doc on the Wiki:
> http://www.cmake.org/Wiki/CMake#CPack
>
> If you want to do some specific adjustment depending on the CPack generator used
> you may use a CPACK_PROJECT_CONFIG_FILE see doc here:
> http://www.cmake.org/Wiki/CMake:CPackPackageGenerators#Overall_usage_.28common_to_all_generators.29
>
> I hope this helps.

Thanks a lot! With three lines in CMakeLists.txt I now get the same
behaviour for 'make install' and the package generators:

set(CPACK_INCLUDE_TOPLEVEL_DIRECTORY 0) # don't prepend package name
etc. (for archive generators)
set(CPACK_PACKAGING_INSTALL_PREFIX ${CMAKE_INSTALL_PREFIX})
set(CPACK_SET_DESTDIR ON) # fixes absolute paths for archive generators

IMHO, it would be really sweet if cpack could default to
CPACK_SET_DESTDIR=ON and
CPACK_PACKAGING_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}. But I don't
know what that would mean in terms of backwards compatibility
breakage...

Well anyway, thanks for helping me out :-)

Best regards,
Bjørn Forsman