Firstly, check to see if perlbrew's perl is the one being used (as well as cpan) and not system perl: which perl; which cpan.

Secondly, check to see if the modules you installed via perlbrew's cpan/cpanm do install in their proper locations and that the correct modules are loaded (where "incorrect" modules are those loaded from system perl's INC places). Useful here is the @INC : perl -e 'print "@INC"'

Thirdly, the other interference from system perl+tk would be that their binary libraries (.so, .dylib) are loaded instead of perlbrew's perl+tk. You can check/affect that with the env vars: LD_LIBRARY_PATH and DYLD_LIBRARY_PATH and, better, sieve through the output of strace perl (consequently: strace /Library/Developer/CommandLineTools/usr/bin/make  all-am (note: I am not sure if this command will recursively strace all the calls inside the Makefile).

I think with the above you can detect where libraries and modules are loaded from, and, therefore, eliminate the possibility of "interference" from system perl+tk.

Using an older macOS is a bless and a curse: the newer (13.+) are locking the system with the so-called SIP with a really annoying effect: (DY)LD_LIBRARY_PATH env vars are *forbidden* (by the cupertino directorate) to be passed to executables, so this DYLD_LIBRARY_PATH=my-good-tk-libraries make all-am will have no effect and still be looking in /usr/lib first. The curse of course is that nothing works and the one daring to use older hardware feels like a leper, not least by the various forums' support.

bw, bliako

In the original post, you can see that I call the correct cpan using the perlbrew cpan full path name, which was built using the perlbrew perl, so I expected that all to work correctly.

However, running which perl; which cpan from my command line shows me the system commands being found first. I will try fixing this so that perlbrew commands are in my environment first and see if that helps.

Also, checking where the modules were installed shows the following:

/opt/homebrew/Cellar/perl/5.36.0/bin/perl -e 'print "@INC"'
/opt/homebrew/opt/perl/lib/perl5/site_perl/5.36/darwin-thread-multi-2l
+evel /opt/homebrew/opt/perl/lib/perl5/site_perl/5.36 /opt/homebrew/op
+t/perl/lib/perl5/5.36/darwin-thread-multi-2level /opt/homebrew/opt/pe
+rl/lib/perl5/5.36 /opt/homebrew/lib/perl5/site_perl/5.36/darwin-threa
+d-multi-2level /opt/homebrew/lib/perl5/site_perl/5.36
[download]

There are no environment variables in my shell for LD_LIBRARY_PATH or DYLD_LIBRARY_PATH but maybe cpan adds them somehow?

I will try using strace and see if the output indicates if the old system tcl-tk libraries are being used and post the results here.

$ cd /Users/cmv/.cpan/build/Tk-804.036-0/PNG
$ /opt/homebrew/Cellar/perl/5.36.0/bin/perl -w t/cmv.t
1..5
ok 1 - use Tk::PNG;
Photo 1
zsh: segmentation fault  /opt/homebrew/Cellar/perl/5.36.0/bin/perl -w 
+t/cmv.t
[download]

Here are some relavent lines from my cmv.t file

...
use_ok('Tk::PNG');

my $file = (@ARGV) ? shift : "$FindBin::RealBin/../pngtest.png";

my $mw = MainWindow->new;
$mw->geometry('+10+10');
$mw->update;            #### Added by --cmv
sleep 10;

{
print STDERR "Photo 1\n";    #### Added by --cmv
    my $image = $mw->Photo('-format' => "png", -file => $file);
print STDERR "Photo 2\n";    #### Added by --cmv
    ok($image, "Loaded PNG image from $file");
print STDERR "Photo 3\n";    #### Added by --cmv
    $mw->Label(-image => $image)->pack;
print STDERR "Photo 4\n";    #### Added by --cmv
    $mw->update;
print STDERR "Photo 5\n";    #### Added by --cmv
}
...
[download]

Note 1: The $mw->update; line does cause the Tk mainwindow to show up on my screen!!!

Note 2: The problem seems to be loading the PNG photo. More digging needed here.

Many thanks to all who have provided pointers and help!

-Craig

I have verified that this is only an issue with the PNG code provided as part of pTk. I was able to manually run tests on all the rest of the pTk code, which was almost 100% successful, but have not yet had the time to nail down the specific cause of this PNG issue.

Here is where I'm currently at:

The offending line, causing the segfault, in the basic.t test file is:

my $image = $mw->Photo('-format' => "png", -file => $file);

Where:

file="~/.cpan/build/Tk-804.036-0/PNG/t/../pngtest.png"

When a segmentation fault occurs on a Mac, a *.ips file is created in ~/Library/Logs/DiagnosticReports providing more details on the fault. Stack frame analysis from this data yields:

"frames":[
{"imageOffset":9468,"symbol":"_longjmp","symbolLocation":72,"imageIndex":0}, {"imageOffset":18446639227543793010,"imageIndex":1}, {"imageOffset":166568,"symbol":"png_error","symbolLocation":420,"imageIndex":2}, {"imageOffset":91072,"symbol":"png_create_read_struct_2","symbolLocation":636,"imageIndex":2}, {"imageOffset":90424,"symbol":"png_create_read_struct","symbolLocation":60,"imageIndex":2}, {"imageOffset":10552,"symbol":"ChnReadPNG","symbolLocation":112,"imageIndex":2}, {"imageOffset":419820,"symbol":"ImgPhotoConfigureMaster","symbolLocation":1176,"imageIndex":3}, {"imageOffset":398084,"symbol":"ImgPhotoCreate","symbolLocation":204,"imageIndex":3}, {"imageOffset":366856,"symbol":"Tk_ImageObjCmd","symbolLocation":1664,"imageIndex":3}, {"imageOffset":88836,"symbol":"Call_Tk","symbolLocation":624,"imageIndex":3}, {"imageOffset":133540,"symbol":"XStoImage","symbolLocation":608,"imageIndex":3}, {"imageOffset":752088,"symbol":"Perl_pp_entersub","symbolLocation":1696,"imageIndex":4}, {"imageOffset":712144,"symbol":"Perl_runops_standard","symbolLocation":32,"imageIndex":4}, {"imageOffset":157920,"symbol":"S_run_body","symbolLocation":116,"imageIndex":4}, {"imageOffset":157800,"symbol":"perl_run","symbolLocation":648,"imageIndex":4}, {"imageOffset":15952,"symbol":"main","symbolLocation":180,"imageIndex":5}, {"imageOffset":20620,"symbol":"start","symbolLocation":520,"imageIndex":6}

As you can see we did hit png_error() before heading to imagIndex(), then to _longjmp, which I'm guessing is the cause of the segfault.

Since I'm not currently using PNG images for anything in my code, I just stubbed out the two test files and installed pTk via CPAN as you normally would. Everything else seems to be working fine.

I would like to eventually figure out why this code segfaults on macOS Monterey (12.6) with Apple M1 chip, and feedback to the PNG group on what needs to be fixed.

Any suggestions on what to try next would be welcome!

Thanks

-Craig

if a test is failing, run the file individually, and identify the file for us

dot dot dot isnt a full path name ;)

Here is the relavent pstree output for the hanging processes:

...
       \-+= 03627 cmv /Library/Developer/CommandLineTools/usr/bin/make
+ test
         \-+- 05377 cmv /bin/sh -c cd PNG && make test_dynamic LIBPERL
+_A="libperl.a" LINKTYPE="dynamic" OPTIMIZE="-O3" PREFIX="/opt/homebre
+w/opt/perl" PASTHRU_DEFINE=' ' PASTHRU_INC='-I/usr/X11R6/include -I/o
+pt/X11/include/freetype2 '
           \-+- 05378 cmv /Library/Developer/CommandLineTools/usr/bin/
+make test_dynamic LIBPERL_A=libperl.a LINKTYPE=dynamic OPTIMIZE=-O3 P
+REFIX=/opt/homebrew/opt/perl PASTHRU_DEFINE=  PASTHRU_INC=-I/usr/X11R
+6/include -I/opt/X11/include/freetype2 
             \-+- 05444 cmv /opt/homebrew/Cellar/perl/5.36.0/bin/perl 
+-I../t -MTkTest -e checked_test_harness('../xt', 0, '../blib/lib', '.
+./blib/arch') t/basic.t t/crash.t
               \--- 05446 cmv /opt/homebrew/Cellar/perl/5.36.0/bin/per
+l -w t/basic.t
[download]

Running the following command from the CPAN build directory (/Users/cmv/.cpan/build/Tk-804.036-0) causes the hang:

/bin/sh -c cd PNG && make test_dynamic LIBPERL_A="libperl.a" LINKTYPE=
+"dynamic" OPTIMIZE="-O3" PREFIX="/opt/homebrew/opt/perl" PASTHRU_DEFI
+NE=' ' PASTHRU_INC='-I/usr/X11R6/include -I/opt/X11/include/freetype2
+ '
[download]

The file that it seems to be hanging on is:

/Users/cmv/.cpan/build/Tk-804.036-0/PNG/t/basic.t
[download]

I'm having the same problem. What was the resolution of this error?