gmake install: Windows 11, gcc 12: Use of uninitialized value $str in substitution (s///) at ..\lib/Pod/Simple/XHTML.pm line 75.

[hakonhagland]

I am trying to install perl from blead on Windows 11 using MinGW-w64 and gcc 12.2 from https://winlibs.com/ (using the MSVCRT runtime library) following a similar approach as in #20096. See also #20391.

After downloading WinLibs to C:\Winlibs64-Gcc12-msvcrt, I needed to rename gnu make binary to gmake.exe:

> copy C:\Winlibs64-Gcc12-msvcrt\mingw64\bin\mingw32-make.exe C:\Winlibs64-Gcc12-msvcrt\mingw64\bin\gmake.exe

This is gcc version 12.2.0, and gnu make version 4.3:

# make sure core.autocrlf in the git config is not set to true before checkout below:
c:\PerlWinLib> git clone https://github.com/Perl/perl5.git  
[...]

c:\PerlWinLib>cd perl5\win32

c:\PerlWinLib\perl5\win32>where gcc
C:\Winlibs64-Gcc12-msvcrt\mingw64\bin\gcc.exe

c:\PerlWinLib\perl5\win32>gcc --version
gcc (MinGW-W64 x86_64-ucrt-posix-seh, built by Brecht Sanders) 12.2.0
Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

C:\PerlWinLib\perl5\win32>where gmake
C:\Winlibs64-Gcc12-msvcrt\mingw64\bin\gmake.exe

c:\PerlWinLib\perl5\win32>gmake --version
GNU Make 4.3
Built for x86_64-w64-mingw32
Copyright (C) 1988-2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

To build perl I needed to set the environment variable CCHOME:

c:\PerlWinLib\perl5\win32>set CCHOME=C:\Winlibs64-Gcc12-msvcrt\mingw64

Now, I was able to build perl and test perl

c:\PerlWinLib\perl5\win32>powershell "gmake 2>&1 | tee gmake.log"
c:\PerlWinLib\perl5\win32>powershell "gmake test 2>&1 | tee gmake-test.log"

The build log file is here: gmake.log, and the test log is here: gmake-test.log

Now, I tried to install perl:

c:\PerlWinLib\perl5\win32>powershell "gmake install 2>&1 | tee gmake-install.log"

which gave the following warning (see line 2108 in the log file):

[...]

..\perl.exe -I..\lib ..\installhtml --podroot=.. --htmldir=.\html \
    --podpath=pod:lib:utils --htmlroot="file://c|\perl\html"\
    --recurse
..\installhtml: Warning both '../lib/ExtUtils/ParseXS.pod' and '../lib/ExtUtils/ParseXS.pm' exist, using pod
Use of uninitialized value $str in substitution (s///) at ..\lib/Pod/Simple/XHTML.pm line 75.
[...]

I guess the first warning that both '../lib/ExtUtils/ParseXS.pod' and '../lib/ExtUtils/ParseXS.pm' exist, is harmless, but the second warning: Use of uninitialized value $str in substitution (s///) at ..\lib/Pod/Simple/XHTML.pm line 75 might deserve some further investigation?

[sisyphus]

I think that warning has been around for a long time. (It happens on my builds, but I no longer take any notice of it.)
AFAIK, it doesn't indicate that there's something broken or in need of fixing.
It should be investigated and silenced, IMO - the same goes for the other warning.

Cheers,
Rob

[jkeenan]

[snip]
..\perl.exe -I..\lib ..\installhtml --podroot=.. --htmldir=.\html
--podpath=pod:lib:utils --htmlroot="file://c|\perl\html"
--recurse
..\installhtml: Warning both '../lib/ExtUtils/ParseXS.pod' and '../lib/ExtUtils/ParseXS.pm' exist, using pod
Use of uninitialized value $str in substitution (s///) at ..\lib/Pod/Simple/XHTML.pm line 75.
[...]

I guess the first warning that `both '../lib/ExtUtils/ParseXS.pod' and '../lib/ExtUtils/ParseXS.pm' exist`, is harmless, but the second warning: `Use of uninitialized value $str in substitution (s///) at ..\lib/Pod/Simple/XHTML.pm line 75` might deserve some further investigation?

This is a bug in Pod::Simple::XHTML which is maintained upstream on CPAN. I have already reported this bug upstream; see perl-pod/pod-simple#135.