Before my 20d2a30f8f ("Makefile: replace perl/Makefile.PL with simple
make rules", 2017-12-10) on an OS package that removed the
private-Error.pm copy we carried around manually removing the OS's
Error.pm would yield:
$ git add -p
Can't locate Error.pm in @INC (you may need to install the Error module) [...]
Now, before this change we'll instead emit this more cryptic error:
$ git add -p
BUG: '/usr/share/perl5/Git/FromCPAN' should be a directory! at /usr/share/perl5/Git/Error.pm line 36.
This is a confusing error. Now if the new NO_PERL_CPAN_FALLBACKS
option is specified and we can't find the module we'll instead emit:
$ /tmp/git/bin/git add -p
BUG: The 'Error' module is not here, but NO_PERL_CPAN_FALLBACKS was set!
[...]
Where [...] is the lengthy explanation seen in the change below, which
explains what the potential breakage is, and how to fix it.
The reason for checking @@NO_PERL_CPAN_FALLBACKS@@] against the empty
string in Perl is as opposed to checking for a boolean value is that
that's (as far as I can tell) make's idea of a string that's set, and
e.g. NO_PERL_CPAN_FALLBACKS=0 is enough to set NO_PERL_CPAN_FALLBACKS.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the CPAN modules that have lived under perl/Git/FromCPAN since my
20d2a30f8f ("Makefile: replace perl/Makefile.PL with simple make
rules", 2017-12-10) to perl/FromCPAN.
A subsequent change will teach the Makefile to only install these
copies of CPAN modules if a flag that distro packagers would like to
set isn't set. Due to how the wildcard globbing is being done it's
much easier to accomplish that if they're moved to their own
directory.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the two wrappers that load from CPAN (local OS) or our own copy
to do so via the same codepath.
I added the Error.pm wrapper in 20d2a30f8f ("Makefile: replace
perl/Makefile.PL with simple make rules", 2017-12-10), and shortly
afterwards Matthieu Moy added a wrapper for Mail::Address in
bd869f67b9 ("send-email: add and use a local copy of Mail::Address",
2018-01-05).
His loader was simpler since Mail::Address doesn't have an "import"
method, but didn't do the same sanity checking; For example, a missing
FromCPAN directory (which OS packages are likely not to have) wouldn't
be explicitly warned about as a "BUG: ...".
Update both to use a common implementation based on the previous
Error.pm loader. Which has been amended to take the module to load as
parameter, as well as whether or not that module has an import
method.
This loader should be generic enough to handle almost all CPAN modules
out there, some use some crazy loading magic and wouldn't like being
wrapped like this, but that would be immediately obvious, and we'd
find out right away since the module wouldn't work at all.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
