Re: [Module-build-general] A better passthrough Makefile.PL

[Ken W. <ke...@ma...>]

On Thursday, October 3, 2002, at 06:54  PM, Dave Rolsky wrote:
> I wanted to create a Makefile.PL that would pass all functionality 
> through
> to Module::Build, _and_ that would make sure that Module::Build got
> installed if necessary.  I also wanted to make sure that the user did 
> not
> have to run "perl Makefile.PL" twice, once for installing Module::Build,
> and once to install the desired module.  Having to do this basically 
> makes
> the install fail with CPAN or CPANPLUS.
>
> Here's what I came up with:
>
>
>   use Cwd;
>   use File::Spec;
>
>   unless (eval { require Module::Build::Compat; 1 }) {
>       require ExtUtils::MakeMaker;
>
>       print "This module required Module::Build to install itself.\n";
>
>       my $yn = ExtUtils::MakeMaker::prompt( '  Install Module::Build', 
> 'y' );
>
>       if ($yn =~ /^y(es)?/i) {
> 	  # save this cause CPAN will chdir all over the place.
> 	  my $cwd = cwd();
> 	  my $makefile = File::Spec->rel2abs($0);
>
> 	  require CPAN;
> 	  CPAN->install('Module::Build');
>
> 	  chdir $cwd
> 	      or die "Cannot chdir to $cwd: $!";
>
> 	  exec( $^X, $makefile, @ARGV )
>       } else {
> 	  warn "Cannot install Thesaurus without Module::Build.  Exiting 
> ...\n";
> 	  exit 0;
>       }
>   }
>
>   require Module::Build::Compat;
>   Module::Build::Compat->run_build_pl( args => \@args );
>   Module::Build::Compat->write_makefile;

I think this is a decent change.  Autrijus, I think it's better to use 
ExtUtils::MakeMaker here than ExtUtils::AutoInstall, simply because the 
user will have the former but probably not the latter.

Actually, I just had an idea - would the following small change work 
(note the 'touch' line, "open $0")?

   unless (eval "use Module::Build::Compat 0.02; 1" ) {
     # Workaround with old CPAN.pm and CPANPLUS.pm
     require ExtUtils::MakeMaker;
     ExtUtils::MakeMaker::WriteMakefile(
       PREREQ_PM => { 'Module::Build::Compat' => 0.02 }
     );
     warn "Warning: prerequisite Module::Build::Compat is not found.\n";
     sleep 2;  # Wait a couple seconds after writing Makefile
     open my($fh), ">> $0"  # Change modification date
       or warn "You may have to run 'perl Makefile.PL' again.";
     exit(0);
   }
   Module::Build::Compat->run_build_pl(args => \@ARGV);
   Module::Build::Compat->write_makefile();

The idea is that it changes the modification time for Makefile.PL to be 
after the Makefile's, so that Makefile.PL gets re-run.  This is kind of 
tough to test out - Dave, how did you test this before?

  -Ken