Could be the perl running your program is not the one you used to compile your extension. Check your perl with -v at the command line, and its @INC with -V

Thanks @1nickt.

I have tried:

perl -e "print \"@INC\""
[download]

And got:

/etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr
+/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /
+usr/local/lib/site_perl
[download]

and perl -v and got:

This is perl 5, version 18, subversion 2 (v5.18.2) built for x86_64-li
+nux-gnu-thread-multi
(with 41 registered patches, see perl -V for more detail)
[download]

Which I think does looks fine.

. I can see the symbol is there when I do:

No, PL_utf8skip is only used there, its not defined there, PL_utf8skip comes from libperl516.so

To see how dlls depend on each other use ldd -v ...so / ldd -v ..so like this (also includes other tips)

Thanks.

I was hoping that libperl.so located in the standard library directory /usr/lib will get resolved by the link flag -lperl and hence make the symbol PL_utf8skip available.

ldd -v /usr/local/lib/perl/5.18.2/auto/Encode/Encode.so

Results:

	linux-vdso.so.1 =>  (0x00007ffcacdc7000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f7c44f87000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f7c45555000)

	Version information:
	/usr/local/lib/perl/5.18.2/auto/Encode/Encode.so:
		libc.so.6 (GLIBC_2.2.5) => /lib/x86_64-linux-gnu/libc.so.6
	/lib/x86_64-linux-gnu/libc.so.6:
		ld-linux-x86-64.so.2 (GLIBC_2.3) => /lib64/ld-linux-x86-64.so.2
		ld-linux-x86-64.so.2 (GLIBC_PRIVATE) => /lib64/ld-linux-x86-64.so.2

Well, for whatever reason, Encode.so doesn't appear linked to libperl.so ... thats weird, do the other .so's link to libperl? Like pymechanize.o or whatever it is you're generating?

ikegami: Did you follow the instructions at all?

Do you think XSLoader could run and produce an error message if the instructions weren't followed?

@ikegami - Yes I did. Thanks.

I am now looking into an option of explicitly compiling header perl.h directly into my extension library. But I am getting the error below.

My Error:

x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -g -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -fPIC -I/usr/lib/perl/5.18/CORE -I/usr/include -I/usr/local/include -I/usr/include/python3.4m -I/home/losintikfos/git/testproj/env/include/python3.4m -c src/pymechanize.c -o build/temp.linux-x86_64-3.4/src/pymechanize.o -O0 -g3 -Wall -c -fmessage-length=0 -Wl,-E -fstack-protector -L/usr/local/lib -L/usr/lib/perl/5.18/CORE -lperl -ldl -lm -lpthread -lc -lcrypt -D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/lib/perl/5.18/CORE
In file included from /usr/lib/perl/5.18/CORE/perl.h:2513:0,
                 from src/pymechanize.c:297:
/usr/lib/perl/5.18/CORE/handy.h:873:1: error: unknown type name ‘EXTCONST’
 EXTCONST U32 PL_charclass[];
 ^
/usr/lib/perl/5.18/CORE/handy.h:873:14: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘PL_charclass’
 EXTCONST U32 PL_charclass[];
              ^
In file included from /usr/lib/perl/5.18/CORE/regexp.h:21:0,
                 from /usr/lib/perl/5.18/CORE/perl.h:3472,
                 from src/pymechanize.c:297:
/usr/lib/perl/5.18/CORE/utf8.h:100:10: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘unsigned’
 EXTCONST unsigned char PL_utf8skip[];
          ^
In file included from src/pymechanize.c:297:0:
/usr/lib/perl/5.18/CORE/perl.h:4254:10: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘char’
 EXTCONST char PL_warn_uninit[]
          ^
/usr/lib/perl/5.18/CORE/perl.h:4256:10: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘char’
 EXTCONST char PL_warn_uninit_sv[]
          ^
/usr/lib/perl/5.18/CORE/perl.h:4258:10: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘char’
 EXTCONST char PL_warn_nosemi[]
          ^
/usr/lib/perl/5.18/CORE/perl.h:4260:10: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘char’
 EXTCONST char PL_warn_reserved[]
          ^
/usr/lib/perl/5.18/CORE/perl.h:4262:10: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘char

....

Any ideas monks.