Re: [gentoo-dev] [PATCH 06/12] python-utils-r1.eclass: Don't die in python_fix_shebang if all fixed

[James Le Cuirot]

On Fri, 04 Jan 2019 19:26:34 +0100
Michał Górny <mgorny@g.o> wrote:

> On Fri, 2019-01-04 at 13:10 -0500, Mike Gilbert wrote:
> > On Fri, Jan 4, 2019 at 10:55 AM Michał Górny <mgorny@g.o> wrote:
> > >
> > > On Thu, 2019-01-03 at 21:39 +0000, James Le Cuirot wrote:
> > > > Shebangs may need fixing on prefix systems or when cross-building but
> > > > not at other times.
> > > >
> > > > Signed-off-by: James Le Cuirot <chewi@g.o>
> > > > ---
> > > >  eclass/python-utils-r1.eclass | 8 ++------
> > > >  1 file changed, 2 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/eclass/python-utils-r1.eclass b/eclass/python-utils-r1.eclass
> > > > index 19cfaf2798ab..91e457f3cf14 100644
> > > > --- a/eclass/python-utils-r1.eclass
> > > > +++ b/eclass/python-utils-r1.eclass
> > > > @@ -1328,16 +1328,12 @@ python_fix_shebang() {
> > > >                       fi
> > > >               done < <(find -H "${path}" -type f -print0 || die)
> > > >
> > > > -             if [[ ! ${any_fixed} ]]; then
> > > > +             if [[ ! ${any_fixed} && ! ${any_correct} ]]; then
> > > >                       local cmd=eerror
> > > >                       [[ ${EAPI:-0} == [012345] ]] && cmd=eqawarn
> > > >
> > > >                       "${cmd}" "QA warning: ${FUNCNAME}, ${path#${D%/}} did not match any fixable files."
> > > > -                     if [[ ${any_correct} ]]; then
> > > > -                             "${cmd}" "All files have ${EPYTHON} shebang already."
> > > > -                     else
> > > > -                             "${cmd}" "There are no Python files in specified directory."
> > > > -                     fi
> > > > +                     "${cmd}" "There are no Python files in specified directory."
> > > >
> > > >                       [[ ${cmd} == eerror ]] && die "${FUNCNAME} did not match any fixable files (QA warning fatal in EAPI ${EAPI})"
> > > >               fi
> > >
> > > Sounds like you're introducing breakage, then abusing a function to fix
> > > your breakage, then killing a useful diagnostic because you've just
> > > broken it.
> >
> > I'm unable to make sense of what you are trying to say here. Is there
> > something wrong with this patch, or are you making a general comment
> > on the patch series?
> >
>
> Original usage: rewrite 'python' to 'pythonX.Y', etc. on static files.
> Throws an error if you try to use for files that have correct shebang
> already.
>
> Now:
>
> 1. Due to PYTHON override, generated files frequently have wrong
> shebangs.
>
> 2. python_fix_shebang is modified to fix this -- orthogonal behavior is
> introduced.
>
> 3. Now diagnostic on files with correct shebang is gone because it
> conflicts with the orthogonal behavior added here.

The diagnostic is a problem even without my changes.

It's quite likely upstream could hardcode a shebang like
#!/usr/bin/python2.7, which does not need to be modified on normal
systems but does on prefixed systems. 

What about hardcoding #!/usr/bin/python3.6? This would need correcting
against 3.7 but would fall foul of the diagnostic when using 3.6.

The cross-prefix issue where the shebang points to BROOT rather than
EPREFIX could also already happen now.

-- 
James Le Cuirot (chewi)
Gentoo Linux Developer