[perl #125603] failed to compile perl5 when path includes the string "blib"

Post by James E Keenan via RT

PathTools is a library which is distributed with the Perl 5 core, but
also available on CPAN (http://search.cpan.org/dist/PathTools/). The
fact that it is in the 'dist/' means that it is primarily maintained
by the Perl 5 Porters.
However, any deficiency in dist/PathTools/Makefile.PL would *at most*
affect the compilation of the PathTools library. It would *not*
affect the compilation of perl 5 as a whole. So I doubt that a change
to that Makefile.PL would be the remedy to your problem -- if indeed
your problem is a failure of perl5 as a whole?
Could you please post, as an attachment to this bug report (or email
attachment), the complete arguments you used to configure Perl and all
the output of 'sh ./Configure' and 'make' up to the point where you
experienced a failure?
Also, please let us know your OS; how you are attempting to build Perl
5; etc.
Thank you very much.

I am using Ubuntu 14.04 LTS;

the configure log, make log, and config.h are attached

thanks.

---
via perlbug: queue: perl5 status: open
https://rt.perl.org/Ticket/Display.html?id=125603

rongqing (via RT)

2015-07-13 02:08:58 UTC

# New Ticket Created by rongqing
# Please include the string: [perl #125603]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/Ticket/Display.html?id=125603 >

1. failed to compile perl5 when path includes the string "blib"
Reproduce as below:

#mkdir blib
#cd blib
#unxz perl-5.22.0.tar.xz
#tar -xvf perl-5.22.0.tar
#cd perl-5.22.0
#./Configure -des -Dprefix=./
#make

2. the possible patch is below:
+---
+ dist/PathTools/Makefile.PL | 3 ---
+ 1 file changed, 3 deletions(-)
+
+diff --git a/dist/PathTools/Makefile.PL b/dist/PathTools/Makefile.PL
+index 1b21de4..f562cb2 100644
+--- a/dist/PathTools/Makefile.PL
++++ b/dist/PathTools/Makefile.PL
+@@ -1,6 +1,3 @@
+-
+-BEGIN { @INC = grep {!/blib/} @INC }
+-
+ require 5.005;
+ use ExtUtils::MakeMaker;
+ WriteMakefile
+--
+1.9.1

James E Keenan via RT

2015-07-15 01:58:31 UTC

1. failed to compile perl5 when path includes the string "blib"
#mkdir blib
#cd blib
#unxz perl-5.22.0.tar.xz
#tar -xvf perl-5.22.0.tar
#cd perl-5.22.0
#./Configure -des -Dprefix=./
#make

Is there some reason why you are trying to configure and build perl in a directory whose path ends in 'blib'?

For most Perl modules 'blib' is a directory reserved for the build process. It is something typically created by 'make'. While I suppose there is no law against working in a directory called 'blib', it does seem to be asking for trouble.

Can you explain why you are attempting this?

Thank you very much.

--
James E Keenan (***@cpan.org)

---
via perlbug: queue: perl5 status: open
https://rt.perl.org/Ticket/Display.html?id=125603

Jens Rehsack

2015-07-15 05:58:49 UTC

Post by James E Keenan via RT

1. failed to compile perl5 when path includes the string "blib"
#mkdir blib
#cd blib
#unxz perl-5.22.0.tar.xz
#tar -xvf perl-5.22.0.tar
#cd perl-5.22.0
#./Configure -des -Dprefix=./
#make

Is there some reason why you are trying to configure and build perl in a directory whose path ends in 'blib'?

no special reason;
I are building a Yocto project, which includes perl;
but I can not building this project under a directory whose
path has "blib", since perl will fail to be compiled
I think others must spend lots of effect to find why
compilation failed once he meet this issue.

As far as I understand, Roy is complaining about reserved words in path.

From non-perl developers point of view, failing in configure stage with an
error of a reserved word is found in path would make it clearer for anyone,
but preferred would be a rewrite of the filter only removing the really
issued path components (I expect the current module build area).

blib already computes them, maybe sharing them (our) and PathTools filter
only the desired part?

I don't know about any other project failing because of reserved word in
build path.

Cheers

--
Jens Rehsack - ***@gmail.com

Rongqing Li

2015-07-15 06:59:36 UTC

Post by Jens Rehsack
I don't know about any other project failing because of reserved word in
build path.

Yes, I agree

-Roy

Dave Mitchell

2015-07-16 13:05:21 UTC

Post by Jens Rehsack
I don't know about any other project failing because of reserved word in
build path.

Yes, I agree
-Roy

I agree that perl should build regardless of whether the 4 chars "blib"
are in the build directory path or not; I also agree that removing this
line from Makefile.PL:

BEGIN { @INC = grep {!/blib/} @INC }

will fix the immediate problem. However, since I don't understand what
purpose that line serves / served, I'd be reluctant to remove it.

I would speculate that its trying to avoid picking up files from the blib/
subdir in the module's directory, which presumably may contain rubbish
from a failed earlier build attempt. In which case maybe the grep line
should be changed to

BEGIN { @INC = grep {!/^blib/} @INC }

? By why that would have been thought necessary, I don't know.

The history if this line is that originally PathTools, as part of Cwd,
was in perl core (ext/) and didn't have this line. At some point it was
promoted / moved to cpan/ and used an auto-generated Makefile.PL. Then
at some point (5.19.3), the auto-generated file was replaced with the real
one from the CPAN distribution, which had, at some point, for some reason,
gained that line.

--
In England there is a special word which means the last sunshine
of the summer. That word is "spring".

Jens Rehsack

2015-07-16 13:18:07 UTC

Post by Jens Rehsack
I don't know about any other project failing because of reserved word in
build path.

Yes, I agree
-Roy

I agree that perl should build regardless of whether the 4 chars "blib"
are in the build directory path or not; I also agree that removing this
will fix the immediate problem. However, since I don't understand what
purpose that line serves / served, I'd be reluctant to remove it.

That's why I voted against that patch in open-embedded and pressured for
an RT ;)

It is very reasonable to find the root cause as you started below.

Post by Dave Mitchell
I would speculate that its trying to avoid picking up files from the blib/
subdir in the module's directory, which presumably may contain rubbish
from a failed earlier build attempt. In which case maybe the grep line
should be changed to
? By why that would have been thought necessary, I don't know.
The history if this line is that originally PathTools, as part of Cwd,
was in perl core (ext/) and didn't have this line. At some point it was
promoted / moved to cpan/ and used an auto-generated Makefile.PL. Then
at some point (5.19.3), the auto-generated file was replaced with the real
one from the CPAN distribution, which had, at some point, for some reason,
gained that line.

Maybe Steffen Müller has an idea (especially at PathTools I'm always
confused whether it's first updated in core and than mirrored to 2nd
life on CPAN or vice versa), or Leon Timmermans or David Golden (who
was responsible for Module::Build::Compat version 0.2808_01? Oh my, it
was Ken Williams - maybe one should ask him or simply regenerate ...)

Cheers

--
Jens Rehsack - ***@gmail.com

H.Merijn Brand

2015-07-21 12:53:31 UTC

Post by Jens Rehsack
I don't know about any other project failing because of reserved word in
build path.

Yes, I agree
-Roy

I agree that perl should build regardless of whether the 4 chars "blib"
are in the build directory path or not; I also agree that removing this

That is wrong anyway, it should most likely be /\bblib\b/. I see no
reason whatsoever to skipp "/foo/blibber/duh" or "/foo/foblib/ong"

Post by Dave Mitchell
will fix the immediate problem. However, since I don't understand what
purpose that line serves / served, I'd be reluctant to remove it.
I would speculate that its trying to avoid picking up files from the blib/
subdir in the module's directory, which presumably may contain rubbish
from a failed earlier build attempt. In which case maybe the grep line
should be changed to
? By why that would have been thought necessary, I don't know.
The history if this line is that originally PathTools, as part of Cwd,
was in perl core (ext/) and didn't have this line. At some point it was
promoted / moved to cpan/ and used an auto-generated Makefile.PL. Then
at some point (5.19.3), the auto-generated file was replaced with the real
one from the CPAN distribution, which had, at some point, for some reason,
gained that line.

--
H.Merijn Brand http://tux.nl Perl Monger http://amsterdam.pm.org/
using perl5.00307 .. 5.21 porting perl5 on HP-UX, AIX, and openSUSE
http://mirrors.develooper.com/hpux/ http://www.test-smoke.org/
http://qa.perl.org http://www.goldmark.org/jeff/stupid-disclaimers/

Rongqing Li

2015-07-23 01:00:13 UTC

Post by H.Merijn Brand

Post by Jens Rehsack
I don't know about any other project failing because of reserved word in
build path.

Yes, I agree
-Roy

I agree that perl should build regardless of whether the 4 chars "blib"
are in the build directory path or not; I also agree that removing this

That is wrong anyway, it should most likely be /\bblib\b/. I see no
reason whatsoever to skipp "/foo/blibber/duh" or "/foo/foblib/ong"

could you submit a patch for this issue

thanks

-Roy

Rongqing Li

2015-07-29 03:05:15 UTC

Post by H.Merijn Brand

Post by Jens Rehsack
I don't know about any other project failing because of reserved word in
build path.

Yes, I agree
-Roy

I agree that perl should build regardless of whether the 4 chars "blib"
are in the build directory path or not; I also agree that removing this

That is wrong anyway, it should most likely be /\bblib\b/. I see no
reason whatsoever to skipp "/foo/blibber/duh" or "/foo/foblib/ong"

it can not fix all issues to replace /blib/ with /\bblib\b/.

/\bblib\b/ will make the building path "/tmp/xxxxblibyy/" work.
but if the building path has sub-dir blib, it does not work, like
/tmp/blib/

since \b is anchor in perl

-Roy

Jens Rehsack

2015-07-29 06:09:50 UTC

Post by H.Merijn Brand

Post by Jens Rehsack
I don't know about any other project failing because of reserved word in
build path.

Yes, I agree
-Roy

I agree that perl should build regardless of whether the 4 chars "blib"
are in the build directory path or not; I also agree that removing this

That is wrong anyway, it should most likely be /\bblib\b/. I see no
reason whatsoever to skipp "/foo/blibber/duh" or "/foo/foblib/ong"

it can not fix all issues to replace /blib/ with /\bblib\b/.
/\bblib\b/ will make the building path "/tmp/xxxxblibyy/" work.
but if the building path has sub-dir blib, it does not work, like
/tmp/blib/
since \b is anchor in perl

The more I think about the source of the line (Module::Build::Compat),
I vote for completely remove that line and review such imports in future.

Cheers

--
Jens Rehsack - ***@gmail.com

Tony Cook via RT

2015-08-12 06:41:29 UTC

Post by Jens Rehsack
Maybe Steffen Müller has an idea (especially at PathTools I'm always
confused whether it's first updated in core and than mirrored to 2nd
life on CPAN or vice versa), or Leon Timmermans or David Golden (who
was responsible for Module::Build::Compat version 0.2808_01? Oh my, it
was Ken Williams - maybe one should ask him or simply regenerate ...)

The offending line was added to fix this bug:

https://rt.cpan.org/Ticket/Display.html?id=4681

The line wasn't generated by Module::Build::Compat

Tony

---
via perlbug: queue: perl5 status: open
https://rt.perl.org/Ticket/Display.html?id=125603

Jens Rehsack

2015-08-12 13:13:38 UTC