Re: [PATCH v5 07/12] sbuild: support of shell exports from dpkg_runbuild_prepend

[Uladzimir Bely <ubely@ilbers.de>]

In the email from Tuesday, 1 February 2022 21:09:07 +03 user Jan Kiszka wrote:
> On 01.02.22 18:00, Uladzimir Bely wrote:
> > Many of recipes often use shell exports done in dpkg_run_prepend, so that
> > this changed environment is used during build.
> > 
> > While sbuild is performed in isolated environment, we need a way to
> > pass these variables to it. This is done by storing environment before
> > dpkg_runbuild (after prepare_build) and finding just before the actual
> > build what was changed or added.
> > 
> > Signed-off-by: Uladzimir Bely <ubely@ilbers.de>
> > ---
> > 
> >  meta/classes/dpkg.bbclass | 18 ++++++++++++++++++
> >  1 file changed, 18 insertions(+)
> > 
> > diff --git a/meta/classes/dpkg.bbclass b/meta/classes/dpkg.bbclass
> > index 66db7ec5..c252e9b3 100644
> > --- a/meta/classes/dpkg.bbclass
> > +++ b/meta/classes/dpkg.bbclass
> > @@ -29,12 +29,30 @@ do_install_builddeps[lockfiles] +=
> > "${REPO_ISAR_DIR}/isar.lock"> 
> >  addtask devshell after do_install_builddeps
> > 
> > +DPKG_PREBUILD_ENV_FILE="${WORKDIR}/dpkg_prebuild.env"
> > +
> > +do_prepare_build_append() {
> > +    env > ${DPKG_PREBUILD_ENV_FILE}
> > +}
> > +
> > 
> >  # Build package from sources using build script
> >  dpkg_runbuild() {
> >  
> >      E="${@ isar_export_proxies(d)}"
> >      E="${@ isar_export_ccache(d)}"
> >      export PARALLEL_MAKE="${PARALLEL_MAKE}"
> > 
> > +    env | while read -r line; do
> > +        # Filter the same lines
> > +        grep -q "^${line}" ${DPKG_PREBUILD_ENV_FILE} && continue
> > +        # Filter some standard variables
> > +        echo ${line} | grep -q "^HOME=" && continue
> > +        echo ${line} | grep -q "^PWD=" && continue
> > +
> > +        var=$(echo "${line}" | cut -d '=' -f1)
> > +        value=$(echo "${line}" | cut -d '=' -f2-)
> > +        sbuild_export $var "$value"
> > +    done
> > +
> > 
> >      profiles=$(grep "DEB_BUILD_PROFILES" ${SBUILD_CONFIG} | tail -n1 |
> >      cut -d "'" -f 4) if [ ${ISAR_CROSS_COMPILE} -eq 1 ]; then
> >      
> >          profiles="${profiles} cross nocheck"
> 
> So, this basically decouples "Avoid using shell environment during the
> build" and similar conversions downstream from this series, right? It's
> indeed good to have a compat path now.
> 
> However, what are the patterns we want to push? Avoiding exports? Then
> we should probably warn here that this compat path should be avoided and
> might be removed in the future.
> 
> If we want to keep both, we can probably leave several recipes alone in
> that other series.
> 
> Jan

You might be right. Current solution doesn't force users to avoid using 
exports while they are silently supported.

The first internal solution was keeping dpkg_build_export function but also 
passing custom shell exports (from dpkg_runbuild_prepend) to sbuild 
environment. And a warning about migration was shown.

Later I removed this to make new patchset less invasive for downstreams. 
Anyway, if we agree that "dpkg_build_export" (like API function) is more 
preferable, I can get back this solution with warnings.