BrowserUk has asked for the wisdom of the Perl Monks concerning the following question:

Anyone any idea what this error means? 

Layer does not match this perl at C:/perl32/lib/IO/Socket.pm line 80, 
+<> line 1.

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Which is this line: 

    socket($sock,$domain,$type,$protocol) or
        return undef;

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Update: Thanks to perlbiotics, I ran the code with PERLIO_DEBUG=trace.log and these are the last few line of the trace produced: 

828831.pl:9 Layer 1 is crlf
828831.pl:9 openn(crlf,'(Null)','rb',-1,0,0,00000000,1,0140F5C8)
828831.pl:9 Layer 0 is unix
828831.pl:9 Layer 0 is unix
828831.pl:9 PerlIO_push f=034589D0 unix rb 0344E1AC
828831.pl:9 5 _is_ a regular file
828831.pl:9 refcnt_inc: fd 5 refcnt=1
828831.pl:9 PerlIO_push f=034589D0 crlf rb 0344E1AC
C:/perl32/lib/attributes.pm:91 refcnt_dec: fd 5 refcnt=0
C:/perl32/lib/attributes.pm:91 PerlIO_pop f=034589D0 crlf
C:/perl32/lib/attributes.pm:91 PerlIO_pop f=034589D0 unix
828831.pl:70 refcnt_dec: fd 4 refcnt=0
828831.pl:70 PerlIO_pop f=034589CC crlf
828831.pl:70 PerlIO_pop f=034589CC unix
C:/perl32/lib/IO/Socket.pm:80 Layer 1 is crlf
C:/perl32/lib/IO/Socket.pm:80 openn(crlf,'(Null)','rb',4,0,0,00000000,
+0,00000000)
C:/perl32/lib/IO/Socket.pm:80 Layer 0 is unix
C:/perl32/lib/IO/Socket.pm:80 Layer 0 is unix
828831.pl:0 Destruct 0344D834

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Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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Re: Layer does not match this perl
by shmem (Chancellor) on Mar 20, 2010 at 16:56 UTC

    I found at least the location...
    This error is thrown in PerlIO_push() in perlio.c: 

    PerlIO *
PerlIO_push(pTHX_ PerlIO *f, PERLIO_FUNCS_DECL(*tab), const char *mode
+, SV *arg)
{
    if (tab->fsize != sizeof(PerlIO_funcs)) {
      mismatch:
        Perl_croak(aTHX_ "Layer does not match this perl");
    }
    if (tab->size) {
        PerlIOl *l;
        if (tab->size < sizeof(PerlIOl)) {
            goto mismatch;
        }

    [download]

    As for the meaning.... dunno. Has an incompatible IO layer been pushed onto $sock (wild guess) ?

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      Thanks shmem I also found the source.

      The puzzling thing is, the code doesn't give that (or any other) error, when run normally. It only happens when run under the auspices of a binary debugger. Actually just an api tracer along the lines of strace.

      Which implies that the debugger is modifying the contents of memory, except I can run it on any number of other apps without problems. I can even run it perl.exe running any number of other scripts without this problem.

      I suspect that it has something to do with that hookey goto.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]

      *sigh* Reasonable code would be more like: 

          if (tab->fsize != sizeof(PerlIO_funcs)) {
        Perl_croak( aTHX_
            "%s (%d) does not match %s (%d)",
            "PerlIO layer function table size", tab->fsize,
            "size expected by this perl", sizeof(PerlIO_funcs) );
    }
    if (tab->size) {
        PerlIOl *l;
        if (tab->size < sizeof(PerlIOl)) {
            Perl_croak( aTHX_
                "%s (%d) smaller than %s (%d)",
                "PerlIO layer instance size", tab->size,
                "size expected by this perl", sizeof(PerlIOl) );
        }

      [download]

      See also http://perl5.git.perl.org/perl.git/blob?f=pod/perliol.pod.

      - tye        

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