Re: [PATCH v4 00/14] cmake: document, fix on *nix, add CI

From: Phillip Wood <phillip.wood123@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>, git@vger.kernel.org
Cc: Junio C Hamano <gitster@pobox.com>,
	Johannes Schindelin <Johannes.Schindelin@gmx.de>,
	Phillip Wood <phillip.wood123@gmail.com>,
	Victoria Dye <vdye@github.com>,
	Eric Sunshine <ericsunshine@gmail.com>
Subject: Re: [PATCH v4 00/14] cmake: document, fix on *nix, add CI
Date: Tue, 8 Nov 2022 14:42:52 +0000	[thread overview]
Message-ID: <920e1189-99c1-611e-1f0e-7cd33eebf49a@dunelm.org.uk> (raw)
In-Reply-To: <cover-v4-00.14-00000000000-20221103T160255Z-avarab@gmail.com>

On 03/11/2022 16:37, Ævar Arnfjörð Bjarmason wrote:
> This topic gets our tests from passing ~80% with ctest on *nix to
> passing 100%.
> 
> See passing CI job for "cmake + ctest" on Ubuntu at:
> https://github.com/avar/git/actions/runs/3387253536/jobs/5627772317
> 
> See
> http://lore.kernel.org/git/cover-v3-00.12-00000000000-20221101T225022Z-avarab@gmail.com
> for v3.
> 
> Changes since the v3:
> 
>   * A small "while at it" change in 1/14 to make the build output nicer
>     (particularly for "ninja, as it's not verbose). It's just the
>     "msgfmt without --statistics" change we've got in the Makefile
>     already.
> 
>   * Discuss more about -S and -B in 2/14. It's supported by our cmake
>     version(s0.

Thanks, looking the range-diff there seems to be an overlong line in the 
commit message.

>   * Re-arranged the docs in 3/14 as Phillip Wood suggested.

I'm not really seeing that. I suggested putting the windows build 
instructions at the top and inlining the -DCMAKE_BUILD_TYPE discussion 
but looking at the range diff there are still forward references in the 
text.

>   * Used Phillip's write_script(). I tested the emitted files
>     carefully, and they're the same. So something went wrong in my
>     testing before.

I'm glad that works for you now

>   * Use Phillip's file(CHMOD ...) if we have a new enough cmake
>     version, otherwise shell out to "chmod +x".

Kudos for the version test

>   * Use /dev/shm instead of /run/user/`id -u` in an exmaple, and other
>     small things noted in replies to v3.

The range-diff for patch 5 shows a reference to "ctest --test-dir" which 
is not supported by cmake 3.14 but I see that in patch 10 you provide 
alternative instructions for older versions. I would be simpler just to 
provide a single recipe that works everywhere. I think you only need 
"ctest --test-dir" because you changed the build instructions to use 
"cmake -B"

Best Wishes

Phillip

>   * A new 12/14 to do less Windows-specific stuff on *nix, we were
>     looking for "sh" in C:\Program\ Files on *nix...
> 
>   * The GIT_TEST_OPTS integration with cmake-gui now works.
> 
>   * Various small rewording/typo etc. changes to commit messages, see
>     range-diff below.
> 
> Ævar Arnfjörð Bjarmason (14):
>    cmake: don't invoke msgfmt with --statistics
>    cmake: use "-S" and "-B" to specify source and build directories
>    cmake: update instructions for portable CMakeLists.txt
>    cmake: don't copy chainlint.pl to build directory
>    cmake: chmod +x the bin-wrappers/* & SCRIPT_{SH,PERL} & git-p4
>    cmake & test-lib.sh: add a $GIT_SOURCE_DIR variable
>    cmake: set "USE_LIBPCRE2" in "GIT-BUILD-OPTIONS" for test-lib.sh
>    test-lib.sh: support a "GIT_TEST_BUILD_DIR"
>    Makefile + cmake: use environment, not GIT-BUILD-DIR
>    cmake: support GIT_TEST_OPTS, abstract away WIN32 defaults
>    cmake: increase test timeout on Windows only
>    cmake: only look for "sh" in "C:/Program Files" on Windows
>    cmake: copy over git-p4.py for t983[56] perforce test
>    CI: add a "linux-cmake-test" to run cmake & ctest on linux
> 
>   .github/workflows/main.yml          |   3 +
>   .gitignore                          |   1 -
>   Makefile                            |   1 -
>   ci/run-build-and-tests.sh           |  13 +-
>   contrib/buildsystems/CMakeLists.txt | 183 +++++++++++++++++++++-------
>   t/README                            |   3 +
>   t/lib-gettext.sh                    |   2 +-
>   t/lib-gitweb.sh                     |   2 +-
>   t/t7609-mergetool--lib.sh           |   2 +-
>   t/t9902-completion.sh               |  14 +--
>   t/t9903-bash-prompt.sh              |   2 +-
>   t/test-lib.sh                       |  27 +++-
>   12 files changed, 188 insertions(+), 65 deletions(-)
> 
> Range-diff against v3:
>   -:  ----------- >  1:  78dfc2a69b7 cmake: don't invoke msgfmt with --statistics
>   1:  028fa1436d8 !  2:  dd934b0597d cmake: don't "mkdir -p" and "cd" in build instructions
>      @@ Metadata
>       Author: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>       
>        ## Commit message ##
>      -    cmake: don't "mkdir -p" and "cd" in build instructions
>      +    cmake: use "-S" and "-B" to specify source and build directories
>       
>      -    Use the "-S" and -B" flags instead of "mkdir -p" and "cd". The "-p"
>      -    flag to "mkdir" wasn't needed as "contrib/buildsystems" is tracked,
>      -    and the rest of this is now easier to copy/paste into a shell without
>      -    having one's directory changed.
>      +    Rather than the multi-line "mkdir/cd/cmake" recipe provide an
>      +    equivalent one-liner using the "-S" and "-B" options, and then suggest building with "make -C <build-dir>".
>      +
>      +    The rest of these instructions discuss e.g. running tests from our
>      +    top-level "t/" directory, so it's more helpful to avoid changing the
>      +    user's current directory.
>      +
>      +    The "-S" and "-B" options were added in cmake v3.13.0, which is older
>      +    than the version we have a hard dependency on[1].
>      +
>      +    As an aside The "-p" flag to "mkdir" in the pre-image wasn't needed,
>      +    as "contrib/buildsystems" is tracked
>      +
>      +    1. 061c2240b1b (Introduce CMake support for configuring Git, 2020-06-12)
>       
>           Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>       
>      @@ contrib/buildsystems/CMakeLists.txt: NOTE: -DCMAKE_BUILD_TYPE is optional. For m
>        This process generates a Makefile(Linux/*BSD/MacOS) , Visual Studio solution(Windows) by default.
>       -Run `make` to build Git on Linux/*BSD/MacOS.
>       -Open git.sln on Windows and build Git.
>      -+Run `make -C contrib/buildsystems` to build Git on Linux/*BSD/MacOS.
>      ++Run `make -C contrib/buildsystems/out` to build Git on Linux/*BSD/MacOS.
>       +Open contrib/buildsystems/git.sln on Windows and build Git.
>        
>        NOTE: By default CMake uses Makefile as the build tool on Linux and Visual Studio in Windows,
>   2:  7a21f4aa24c !  3:  6f0eae7a02a cmake: update instructions for portable CMakeLists.txt
>      @@ contrib/buildsystems/CMakeLists.txt
>       +alternative.
>       +
>       +The primary use-case for maintaining this CMake build recipe is to
>      -+have nicer IDE integration on Windows. To get Visual Studio-specific
>      -+instructions see "== Visual Studio & Windows ==" below.
>      ++have nicer IDE integration on Windows.
>       +
>       +== Creating a build recipe ==
>       +
>      -+To create the build recipe run:
>      ++The "cmake" command creates a build file from this recipe:
>       +
>       +    cmake -S contrib/buildsystems -B contrib/buildsystems/out -DCMAKE_BUILD_TYPE=Release
>       +
>      -+For alternative "-DCMAKE_BUILD_TYPE=<type>" flags see instructions
>      -+under the "== -DCMAKE_BUILD_TYPE=<type> ==" heading below.
>      ++Running this will create files in the contrib/buildsystems/out
>      ++directory (our top-level .gitignore file knows to ignore contents of
>      ++this directory).
>       +
>      -+== Building ==
>      ++See "cmake options" below for a discussion of
>      ++"-DCMAKE_BUILD_TYPE=Release" and other options to "cmake".
>       +
>      -+The "cmake" command creates a build file from this recipe. For Windows
>      -+Open contrib/buildsystems/git.sln and build Git. Or use the
>      -+"msbuild" command-line tool (see our own ".github/workflows/main.yml"
>      -+for a real example):
>      ++== Building with Visual Visual Studio ==
>      ++
>      ++To use this in Visual Studio:
>      +
>      + Open the worktree as a folder. Visual Studio 2019 and later will detect
>      + the CMake configuration automatically and set everything up for you,
>      +@@ contrib/buildsystems/CMakeLists.txt: Note: Visual Studio also has the option of opening `CMakeLists.txt`
>      + directly; Using this option, Visual Studio will not find the source code,
>      + though, therefore the `File>Open>Folder...` option is preferred.
>      +
>      +-Instructions to run CMake manually:
>      ++By default CMake will install vcpkg locally to your source tree on configuration,
>      ++to avoid this, add `-DNO_VCPKG=TRUE` to the command line when configuring.
>      +
>      +-    cmake -S contrib/buildsystems -B contrib/buildsystems/out -DCMAKE_BUILD_TYPE=Release
>      ++== Building on Windows without Visual Studio ==
>      +
>      +-This will build the git binaries in contrib/buildsystems/out
>      +-directory (our top-level .gitignore file knows to ignore contents of
>      +-this directory).
>      ++Open contrib/buildsystems/git.sln and build Git. Or use the "msbuild"
>      ++command-line tool (see our own ".github/workflows/main.yml" for a real
>      ++example):
>       +
>       +	msbuild git.sln
>       +
>      ++== Building on *nix ==
>      ++
>       +On all other platforms running "cmake" will generate a Makefile; to
>       +build with it run:
>       +
>      @@ contrib/buildsystems/CMakeLists.txt
>       +
>       +It's also possible to use other generators, e.g. Ninja has arguably
>       +slightly better output. Add "-G Ninja" to the cmake command above,
>      -+then e.g.:
>      ++then:
>       +
>       +	ninja -C contrib/buildsystems/out
>       +
>      -+== Visual Studio & Windows ==
>      ++== cmake options ==
>       +
>      -+To use this in Visual Studio:
>      ++=== -DCMAKE_BUILD_TYPE=<type> ===
>        
>      - Open the worktree as a folder. Visual Studio 2019 and later will detect
>      - the CMake configuration automatically and set everything up for you,
>      -@@ contrib/buildsystems/CMakeLists.txt: Note: Visual Studio also has the option of opening `CMakeLists.txt`
>      - directly; Using this option, Visual Studio will not find the source code,
>      - though, therefore the `File>Open>Folder...` option is preferred.
>      -
>      --Instructions to run CMake manually:
>      --
>      --    cmake -S contrib/buildsystems -B contrib/buildsystems/out -DCMAKE_BUILD_TYPE=Release
>      --
>      --This will build the git binaries in contrib/buildsystems/out
>      -+Following the instructions above will build the git binaries in the contrib/buildsystems/out
>      - directory (our top-level .gitignore file knows to ignore contents of
>      - this directory).
>      -
>      -+By default CMake will install vcpkg locally to your source tree on configuration,
>      -+to avoid this, add `-DNO_VCPKG=TRUE` to the command line when configuring.
>      -+
>      -+== -DCMAKE_BUILD_TYPE=<type> ==
>      -+
>        Possible build configurations(-DCMAKE_BUILD_TYPE) with corresponding
>        compiler flags
>      - Debug : -g
>       @@ contrib/buildsystems/CMakeLists.txt: empty(default) :
>        
>        NOTE: -DCMAKE_BUILD_TYPE is optional. For multi-config generators like Visual Studio
>        this option is ignored
>       -
>       -This process generates a Makefile(Linux/*BSD/MacOS) , Visual Studio solution(Windows) by default.
>      --Run `make -C contrib/buildsystems` to build Git on Linux/*BSD/MacOS.
>      +-Run `make -C contrib/buildsystems/out` to build Git on Linux/*BSD/MacOS.
>       -Open contrib/buildsystems/git.sln on Windows and build Git.
>       -
>       -NOTE: By default CMake uses Makefile as the build tool on Linux and Visual Studio in Windows,
>   3:  3bfa873e792 =  4:  0f0eb2a76c7 cmake: don't copy chainlint.pl to build directory
>   4:  ad551f53de9 !  5:  eda1c1e95e5 cmake: chmod +x the bin-wrappers/* & SCRIPT_{SH,PERL} & git-p4
>      @@ Commit message
>                   make -C contrib/buildsystems/out &&
>                   ctest --test-dir contrib/buildsystems/out --jobs="$(nproc)" --output-on-failure
>       
>      -    Fails around 20% of our testts on *nix. So even with [3] we'd fail any
>      +    Fails around 20% of our tests on *nix. So even with [3] we'd fail any
>           test that needed to invoke one of our built shell, perl or Python
>           scripts on *nix. E.g. t0012-help.sh would fail on a test that tried to
>           invoke "git web--browse". The equivalent of this (in the "out"
>      @@ Commit message
>           our built "git-p4" wasn't executable, etc. There's also a few other
>           outstanding issues, which will be fixed in subsequent commits.
>       
>      -    This change should ideally use file(CHMOD ...), but the "file(CHMOD"
>      -    feature is much newer than our required cmake version[5].
>      +    Ideally we'd use the file(CHMOD ...) form everywhere, but that syntax
>      +    was introduced in cmake 3.19[4], whereas we only require 3.14. Let's
>      +    provide a fallback behind a version check, so that we'll eventually be
>      +    able to delete the "else" part. Both forms result in the same file
>      +    modes.
>       
>           Before this change:
>       
>      @@ Commit message
>       
>           The remaining failures will be addressed in subsequent commits.
>       
>      -    There was a suggestion of using a function to abstract this away[6],
>      -    which sounds good. But after spending too long trying to get all
>      -    combinations of "${content}" and ${content} (unqoted) in the function
>      -    and its callers working I wasn't able to fix the quoting issues it
>      -    introduced.
>      -
>      -    A lot of this is duplicated already, we can follow-up at some other
>      -    time with refactoring, and address any tricky quoting issues in
>      -    calling function with these parameters then.
>      -
>           1. f31b6244950 (Merge branch 'yw/cmake-updates', 2022-06-07)
>           2. e4597aae659 (run test suite without dashed git-commands in PATH, 2009-12-02)
>           3. 2ea1d8b5563 (cmake: make it easier to diagnose regressions in CTest
>              runs, 2022-10-18)
>      -    4. a30e4c531d9 (Merge branch 'ss/cmake-build', 2020-08-11)
>      -    5. https://cmake.org/cmake/help/latest/command/file.html#chmod
>      -    6. https://lore.kernel.org/git/0fda0e54-0432-7690-74a7-3d1a59923e0c@dunelm.org.uk/
>      +    4. https://cmake.org/cmake/help/latest/command/file.html#chmod
>       
>           Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>       
>      +    write script
>      +
>        ## contrib/buildsystems/CMakeLists.txt ##
>      +@@ contrib/buildsystems/CMakeLists.txt: add_custom_command(OUTPUT ${git_links} ${git_http_links}
>      + 		DEPENDS git git-remote-http)
>      + add_custom_target(git-links ALL DEPENDS ${git_links} ${git_http_links})
>      +
>      ++function(write_script path content)
>      ++	file(WRITE ${path} ${content})
>      ++
>      ++	if("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" VERSION_GREATER_EQUAL "3.19")
>      ++		file(CHMOD ${path} FILE_PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE)
>      ++	else()
>      ++		execute_process(COMMAND chmod +x ${path}
>      ++				RESULT_VARIABLE CHILD_ERROR)
>      ++		if(CHILD_ERROR)
>      ++			message(FATAL_ERROR "failed to chmod +x '${path}': '${CHILD_ERROR}'")
>      ++		endif()
>      ++	endif()
>      ++endfunction()
>      +
>      + #creating required scripts
>      + set(SHELL_PATH /bin/sh)
>       @@ contrib/buildsystems/CMakeLists.txt: foreach(script ${git_shell_scripts})
>      + 	string(REPLACE "# @@BROKEN_PATH_FIX@@" "" content "${content}")
>        	string(REPLACE "@@PERL@@" "${PERL_PATH}" content "${content}")
>        	string(REPLACE "@@PAGER_ENV@@" "LESS=FRX LV=-c" content "${content}")
>      - 	file(WRITE ${CMAKE_BINARY_DIR}/${script} ${content})
>      -+	execute_process(COMMAND chmod +x ${CMAKE_BINARY_DIR}/${script})
>      +-	file(WRITE ${CMAKE_BINARY_DIR}/${script} ${content})
>      ++	write_script(${CMAKE_BINARY_DIR}/${script} "${content}")
>        endforeach()
>        
>        #perl scripts
>       @@ contrib/buildsystems/CMakeLists.txt: foreach(script ${git_perl_scripts})
>      + 	file(STRINGS ${CMAKE_SOURCE_DIR}/${script}.perl content NEWLINE_CONSUME)
>        	string(REPLACE "#!/usr/bin/perl" "#!/usr/bin/perl\n${perl_header}\n" content "${content}")
>        	string(REPLACE "@@GIT_VERSION@@" "${PROJECT_VERSION}" content "${content}")
>      - 	file(WRITE ${CMAKE_BINARY_DIR}/${script} ${content})
>      -+	execute_process(COMMAND chmod +x ${CMAKE_BINARY_DIR}/${script})
>      +-	file(WRITE ${CMAKE_BINARY_DIR}/${script} ${content})
>      ++	write_script(${CMAKE_BINARY_DIR}/${script} "${content}")
>        endforeach()
>        
>        #python script
>        file(STRINGS ${CMAKE_SOURCE_DIR}/git-p4.py content NEWLINE_CONSUME)
>        string(REPLACE "#!/usr/bin/env python" "#!/usr/bin/python" content "${content}")
>      - file(WRITE ${CMAKE_BINARY_DIR}/git-p4 ${content})
>      -+execute_process(COMMAND chmod +x ${CMAKE_BINARY_DIR}/git-p4)
>      +-file(WRITE ${CMAKE_BINARY_DIR}/git-p4 ${content})
>      ++write_script(${CMAKE_BINARY_DIR}/git-p4 "${content}")
>        
>        #perl modules
>        file(GLOB_RECURSE perl_modules "${CMAKE_SOURCE_DIR}/perl/*.pm")
>       @@ contrib/buildsystems/CMakeLists.txt: foreach(script ${wrapper_scripts})
>      + 	file(STRINGS ${CMAKE_SOURCE_DIR}/wrap-for-bin.sh content NEWLINE_CONSUME)
>        	string(REPLACE "@@BUILD_DIR@@" "${CMAKE_BINARY_DIR}" content "${content}")
>        	string(REPLACE "@@PROG@@" "${script}${EXE_EXTENSION}" content "${content}")
>      - 	file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/${script} ${content})
>      -+	execute_process(COMMAND chmod +x ${CMAKE_BINARY_DIR}/bin-wrappers/${script})
>      +-	file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/${script} ${content})
>      ++	write_script(${CMAKE_BINARY_DIR}/bin-wrappers/${script} "${content}")
>        endforeach()
>        
>        foreach(script ${wrapper_test_scripts})
>      -@@ contrib/buildsystems/CMakeLists.txt: foreach(script ${wrapper_test_scripts})
>      + 	file(STRINGS ${CMAKE_SOURCE_DIR}/wrap-for-bin.sh content NEWLINE_CONSUME)
>        	string(REPLACE "@@BUILD_DIR@@" "${CMAKE_BINARY_DIR}" content "${content}")
>        	string(REPLACE "@@PROG@@" "t/helper/${script}${EXE_EXTENSION}" content "${content}")
>      - 	file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/${script} ${content})
>      -+	execute_process(COMMAND chmod +x ${CMAKE_BINARY_DIR}/bin-wrappers/${script})
>      +-	file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/${script} ${content})
>      ++	write_script(${CMAKE_BINARY_DIR}/bin-wrappers/${script} "${content}")
>        endforeach()
>        
>        file(STRINGS ${CMAKE_SOURCE_DIR}/wrap-for-bin.sh content NEWLINE_CONSUME)
>        string(REPLACE "@@BUILD_DIR@@" "${CMAKE_BINARY_DIR}" content "${content}")
>        string(REPLACE "@@PROG@@" "git-cvsserver" content "${content}")
>      - file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/git-cvsserver ${content})
>      -+execute_process(COMMAND chmod +x ${CMAKE_BINARY_DIR}/bin-wrappers/git-cvsserver)
>      +-file(WRITE ${CMAKE_BINARY_DIR}/bin-wrappers/git-cvsserver ${content})
>      ++write_script(${CMAKE_BINARY_DIR}/bin-wrappers/git-cvsserver "${content}")
>        
>        #options for configuring test options
>        option(PERL_TESTS "Perform tests that use perl" ON)
>   5:  5c7b64286ce =  6:  6c254f8cb9f cmake & test-lib.sh: add a $GIT_SOURCE_DIR variable
>   6:  cba90650879 =  7:  1685a58e13a cmake: set "USE_LIBPCRE2" in "GIT-BUILD-OPTIONS" for test-lib.sh
>   7:  bd7fb1eec24 =  8:  87a2c77ee68 test-lib.sh: support a "GIT_TEST_BUILD_DIR"
>   8:  fd3e6be5689 =  9:  6187ded42db Makefile + cmake: use environment, not GIT-BUILD-DIR
>   9:  8a660a2baa4 ! 10:  3ea4a61698e cmake: support GIT_TEST_OPTS, abstract away WIN32 defaults
>      @@ Commit message
>           Windows-specific anymore.
>       
>           So let's set those same options by default on Windows, but do so with
>      -    the set() facility. As noted in cmake's documentation[1] this
>      -    integrates nicely with e.g. cmake-gui.
>      +    the set(... CACHE <type> <docstring>) facility. As noted in cmake's
>      +    documentation[1] this integrates nicely with e.g. cmake-gui.
>       
>           On *nix we don't set any custom options. The change in 2ea1d8b5563
>           didn't discuss why Windows should have divergent defaults with "cmake"
>      @@ Commit message
>                   GIT_TEST_OPTS=-i cmake -S contrib/buildsystems -B contrib/buildsystems/out &&
>                   ctest --jobs=$(nproc) --test-dir contrib/buildsystems/out -R t0071 --verbose
>       
>      +    The "separate_arguments()" here will do the right thing for arguments
>      +    that don't contain whitespace, so e.g. the path to --root="" can't
>      +    have a space in it. There's supposedly a way to work around that with
>      +    separate_arguments(), but it requires features newer than our required
>      +    cmake version, so let's live with that edge case for now.
>      +
>           1. https://cmake.org/cmake/help/latest/command/set.html#set-cache-entry
>       
>           Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>      @@ contrib/buildsystems/CMakeLists.txt: empty(default) :
>       +The tests can also be run with ctest, e.g. after building with "cmake"
>       +and "make" or "msbuild" run, from the top-level e.g.:
>       +
>      ++	# "--test-dir" is new in cmake v3.20, so "(cd
>      ++	# contrib/buildsystems/out && ctest ...)" on older versions.
>       +	ctest --test-dir contrib/buildsystems/out --jobs="$(nproc)"--output-on-failure
>       +
>       +Options can be passed by setting GIT_TEST_OPTIONS before invoking
>       +cmake. E.g. on a Linux system with systemd the tests can be sped up by
>       +using a ramdisk for the scratch files:
>       +
>      -+	GIT_TEST_OPTS="--root=/run/user/$(id -u)/ctest" cmake -S contrib/buildsystems -B contrib/buildsystems/out
>      ++	GIT_TEST_OPTS="--root=/dev/shm/$(id -u)/ctest" cmake -S contrib/buildsystems -B contrib/buildsystems/out
>       +	[...]
>      -+	-- Using user-selected test options: --root=/run/user/1001/ctest
>      ++	-- Using user-selected test options: --root=/dev/shm/<uid>/ctest
>       +
>       +Then running the tests with "ctest" (here with --jobs="$(nproc)"):
>       +
>      @@ contrib/buildsystems/CMakeLists.txt: endif()
>        
>        file(GLOB test_scipts "${CMAKE_SOURCE_DIR}/t/t[0-9]*.sh")
>        
>      -+string(COMPARE NOTEQUAL "$ENV{GIT_TEST_OPTS}" "" HAVE_USER_GIT_TEST_OPTS)
>      -+if(HAVE_USER_GIT_TEST_OPTS)
>      -+	set(GIT_TEST_OPTS "$ENV{GIT_TEST_OPTS}")
>      ++if(DEFINED ENV{GIT_TEST_OPTS})
>      ++	set(GIT_TEST_OPTS "$ENV{GIT_TEST_OPTS}"
>      ++		CACHE STRING "test options, see t/README")
>       +	message(STATUS "Using user-selected test options: ${GIT_TEST_OPTS}")
>       +elseif(WIN32)
>      -+	set(GIT_TEST_OPTS "--no-bin-wrappers --no-chain-lint -vx")
>      ++	set(GIT_TEST_OPTS "--no-bin-wrappers --no-chain-lint -vx"
>      ++		CACHE STRING "test options, see t/README")
>       +	message(STATUS "Using Windowns-specific default test options: ${GIT_TEST_OPTS}")
>       +else()
>      -+	set(GIT_TEST_OPTS "")
>      ++	set(GIT_TEST_OPTS ""
>      ++		CACHE STRING "test options, see t/README")
>       +	message(STATUS "No custom test options selected, set e.g. GIT_TEST_OPTS=\"-vixd\"")
>       +endif()
>       +separate_arguments(GIT_TEST_OPTS)
> 10:  966fec83b77 = 11:  8ccf5c8c265 cmake: increase test timeout on Windows only
>   -:  ----------- > 12:  7b1f10eb4c0 cmake: only look for "sh" in "C:/Program Files" on Windows
> 11:  aad17d8f858 ! 13:  0699e398e89 cmake: copy over git-p4.py for t983[56] perforce test
>      @@ Commit message
>           Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>       
>        ## contrib/buildsystems/CMakeLists.txt ##
>      -@@ contrib/buildsystems/CMakeLists.txt: file(STRINGS ${CMAKE_SOURCE_DIR}/git-p4.py content NEWLINE_CONSUME)
>      +@@ contrib/buildsystems/CMakeLists.txt: endforeach()
>      + file(STRINGS ${CMAKE_SOURCE_DIR}/git-p4.py content NEWLINE_CONSUME)
>        string(REPLACE "#!/usr/bin/env python" "#!/usr/bin/python" content "${content}")
>      - file(WRITE ${CMAKE_BINARY_DIR}/git-p4 ${content})
>      - execute_process(COMMAND chmod +x ${CMAKE_BINARY_DIR}/git-p4)
>      + write_script(${CMAKE_BINARY_DIR}/git-p4 "${content}")
>       +file(COPY ${CMAKE_SOURCE_DIR}/git-p4.py DESTINATION ${CMAKE_BINARY_DIR}/)
>        
>        #perl modules
> 12:  c27f620dfa3 = 14:  277028678c8 CI: add a "linux-cmake-test" to run cmake & ctest on linux