Re: [pacman-dev] [PATCH v3] makepkg: respect $SOURCE_DATE_EPOCH to activate reproducible builds

On 24/08/17 07:12, Eli Schwartz wrote:

If SOURCE_DATE_EPOCH is set, `touch` all source files before running build() to fix the modification times. This works around build systems and compilers that embed the file modification times into the file contents of release artifacts.

Signed-off-by: Eli Schwartz ---

v3: add makepkg(8) documentation

doc/makepkg.8.txt | 16 ++++++++++++++++ scripts/makepkg.sh.in | 14 +++++++++++++- 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/doc/makepkg.8.txt b/doc/makepkg.8.txt index 2dff1b19..4258e6bd 100644 --- a/doc/makepkg.8.txt +++ b/doc/makepkg.8.txt @@ -206,6 +206,7 @@ Options *\--printsrcinfo*:: Generate and print the SRCINFO file to stdout.

+ Additional Features ------------------- makepkg supports building development versions of packages without having to @@ -214,6 +215,19 @@ separate utility 'versionpkg'. See linkman:PKGBUILD[5] for details on how to set up a development PKGBUILD.

+Reproducibility +--------------- +makepkg is designed to be compatible with +link:https://reproducible-builds.org/docs/[Reproducible Builds]. If the +**SOURCE_DATE_EPOCH** environment variable is set, it will be exported to +subprocesses, and source and package file modification times and package +metadata will be unified based on the timestamp specified. + +If the **SOURCE_DATE_EPOCH** environment variable is not set, makepkg will use +its own start date for internal use, but is not responsible for ensuring the +package files themselves are built reproducibly. +

I don't like the phrasing there. How about : If the **SOURCE_DATE_EPOCH** environment variable is not set, makepkg will use its own start date for internal use, but will not unify source file timestamps before building.

+ Environment Variables --------------------- **PACMAN**:: @@ -265,6 +279,8 @@ Environment Variables Specify a key to use when signing packages, overriding the GPGKEY setting in linkman:makepkg.conf[5]

+**SOURCE_DATE_EPOCH=**"<date>":: + Used for link:https://reproducible-builds.org/docs/[Reproducible Builds].

Configuration ------------- diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in index 20e9dd7e..77d39ca5 100644 --- a/scripts/makepkg.sh.in +++ b/scripts/makepkg.sh.in @@ -79,6 +79,7 @@ PKGFUNC=0 PKGVERFUNC=0 PREPAREFUNC=0 REPKG=0 +REPRODUCIBLE=0 RMDEPS=0 SKIPCHECKSUMS=0 SKIPPGPCHECK=0 @@ -87,7 +88,12 @@ SPLITPKG=0 SOURCEONLY=0 VERIFYSOURCE=0

-export SOURCE_DATE_EPOCH=${SOURCE_DATE_EPOCH:-$(date +%s)} +if [[ -n $SOURCE_DATE_EPOCH ]]; then + REPRODUCIBLE=1 +else + SOURCE_DATE_EPOCH=$(date +%s) +fi +export SOURCE_DATE_EPOCH

PACMAN_OPTS=()

@@ -475,6 +481,12 @@ run_prepare() { }

run_build() { + if (( REPRODUCIBLE )); then + # We have activated reproducible builds, so unify source times before + # building + find "$srcdir" -exec touch -h -d @$SOURCE_DATE_EPOCH {} + + fi +

I don't like this in run_build(). That will introduce an undocumented requirement that a PKGBUILD has a build() function to have its source file timestamps unified. I am happy with the location suggested here: https://github.com/anthraxx/pacman/commit/520acf93

run_function_safe "build" }