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DEBREPRO(1) DEBREPRO(1)

NAME

debrepro - reproducibility tester for Debian packages

SYNOPSIS

debrepro [OPTIONS] [SOURCEDIR]

DESCRIPTION

debrepro will build a given source directory twice, with a set of variations between the first and the second build, and compare the produced binary packages. If diffoscope is installed, it is used to compare non-matching binaries. If disorderfs is installed, it is used during the build to inject non-determinism in filesystem listing operations.

SOURCEDIR must be a directory containing an unpacked Debian source package. If SOURCEDIR is omitted, the current directory is assumed.

OUTPUT DIRECTORY

At the very end of a build, debrepro will inform the location of the output directory where the build artifacts can be found. In that directory, you will find:
$OUTPUTDIR/first
Contains the results of the first build, including a copy of the source tree, and the resulting binary packages.
$OUTPUTDIR/first/build.sh
Contains the exact build script that was used in the first build.
$OUTPUTDIR/second
Contains the results of the second build, including a copy of the source tree, and the resulting binary packages.
$OUTPUTDIR/second/build.sh
Contains the exact build script that was used in the second build.

Taking a diff(1) between $OUTPUTDIR /first/build.sh and $OUTPUTDIR/second/build.sh is an excellent way of figuring out exactly what changed between the two builds.

SUPPORTED VARIATIONS

user
The $USER environment variable will contain different values between the first and second builds.
path
During the second build, a fake, non-existing directory will be appended to the $PATH environment variable.
umask
The builds will use different umask settings.
locale
Both $LC_ALL and $LANG will be different across the two builds.
timezone
$TZ will be different across builds.
filesystem-ordering
If disorderfs is installed, both builds will be done under a disorderfs overlay directory. This will cause filesystem listing operations to be return items in a non-deterministic order.
time
The second build will be executed 213 days, 7 hours and 13 minutes in the future with regards to the current time (using faketime(1)).

OPTIONS

-s VARIATION, --skip VARIATION
Don't perform the named VARIATION. Variation names are the ones used in their description in section SUPPORTED VARIATIONS.
-b COMMAND, --before-second-build COMMAND
Run COMMAND before performing the second build. This can be used for example to apply a patch to a source tree for the second build, and check whether (or how) the resulting binaries are affected.

Examples:

  $ debrepro --before-second-build "git checkout branch-with-changes"

  $ debrepro --before-second-build "patch -p1 < /path/to/patch"
-t TIME, --timeout TIME
Apply a timeout to all builds. TIME must be a time specification compatible with GNU timeout(1).
-h, --help
Display this help message and exit.

EXIT STATUS

0
Package is reproducible.

Reproducible here means that the two builds produced the exactly the same binaries, under the set of variations that debrepro tests. Other sources of non-determinism in builds that are not yet tested might still affect builds in the wild.

1
Package is not reproducible.
2
The given input is not a valid Debian source package.
3
Required programs are missing.

SEE ALSO

diffoscope (1), disorderfs (1), timeout(1)

AUTHOR

Antonio Terceiro <terceiro@debian.org>.
2021-07-18 Debian Utilities