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问题:

I am trying to install mod_perl2 with below configuration:
OS: CentOS release 5.5 (Final)
Uname -a result: x86_64 x86_64 x86_64 GNU/Linux
Perl version: v5.8.8 built for x86_64-linux-thread-multi
apache version: Apache/2.2.3
I have downloaded mod_perl2 from Cpan site
when I try to run the "perl Makefile.PL MP_APXS=/usr/local/httpd/bin/apxs" it gives below output:

Subroutine set_version redefined at ./Makefile.PL line 137.
[ info] generating script t/TEST
[ info] generating script ./t/cgi-bin/cookies.pl
[ info] generating script ./t/cgi-bin/next_available_port.pl
Checking for Cwd...ok
Checking for File::Spec...ok
[ info] generating script t/TEST
Generating a Unix-style Makefile
Writing Makefile for mod_perl2
[warning] mod_perl dso library will be built as mod_perl.so
[warning] You'll need to add the following to httpd.conf:
[warning]
[warning] LoadModule perl_module modules/mod_perl.so
[warning]
[warning] depending on your build, mod_perl might not live in
[warning] the modules/ directory.

[warning] Check the results of
[warning]
[warning] $ /usr/local/httpd/bin/apxs -q LIBEXECDIR
[warning] [warning] and adjust the LoadModule directive accordingly.

After "make" command runs below error occurs:
modperl_env.c: In function ‘modperl_env_magic_local_all’:
modperl_env.c:544: error: ‘MGf_LOCAL’ undeclared (first use in this function)
modperl_env.c:544: error: (Each undeclared identifier is reported only once
modperl_env.c:544: error: for each function it appears in.)
modperl_env.c: At top level:
modperl_env.c:642: warning: excess elements in struct initializer
modperl_env.c:642: warning: (near initialization for ‘MP_vtbl_env’)
modperl_env.c: In function ‘modperl_env_init’:
modperl_env.c:661: warning: passing argument 2 of ‘Perl_mg_find’ discards
qualifiers from pointer target type
modperl_env.c:673: warning: implicit declaration of function ‘mg_free_type’
modperl_env.c:678: error: ‘MGf_LOCAL’ undeclared (first use in this function)
modperl_env.c: In function ‘modperl_env_unload’:
modperl_env.c:690: warning: passing argument 2 of ‘Perl_mg_find’ discards
qualifiers from pointer target type
make1: * [modperl_env.lo] Error 1
make1: Leaving directory `/opt/mod_perl-2.0.10/src/modules/perl'
make: * [modperl_lib] Error 2

any help is appriciated, if i have asked somthing wrong please guide further (no down votes please :) )

回答1:

This constant as been introduced in perl 5.9.3, and mod_perl use it from 2.0.10.

http://search.cpan.org/~vpit/Variable-Magic-0.62/lib/Variable/Magic.pm#MGf_LOCAL https://perl5.git.perl.org/perl.git/commit/a5063e7cd8fef802efd25ffe9df2c3748f4254f6 https://github.com/apache/mod_perl/commit/82827132efd3c2e25cc413c85af61bb63375da6e https://perldoc.perl.org/perlguts.html

to overcome this you must modify mod_perl to use this constant conditionaly of the perl version:

diff -ruw mod_perl-2.0.11/src/modules/perl/modperl_env.c mod_perl-2.0.11.patched/src/modules/perl/modperl_env.c
--- mod_perl-2.0.11/src/modules/perl/modperl_env.c      2017-12-06 11:08:55.000000000 -0500
+++ mod_perl-2.0.11.patched/src/modules/perl/modperl_env.c      2018-03-27 15:02:14.174790000 -0400
@@ -541,7 +541,9 @@
     nmg = sv_magicext(nsv, mg->mg_obj, mg->mg_type, &MP_vtbl_env, (char*)NULL, 0);
     nmg->mg_ptr = mg->mg_ptr;
     nmg->mg_flags |= MGf_COPY;
+#if MP_PERL_VERSION_AT_LEAST(5, 9, 3)
     nmg->mg_flags |= MGf_LOCAL;
+#endif

     return 1;
 }
@@ -679,7 +681,9 @@
     /* Add our version instead */
     mg = sv_magicext((SV*)ENVHV, (SV*)NULL, PERL_MAGIC_env, &MP_vtbl_env, (char*)NULL, 0);
     mg->mg_flags |= MGf_COPY;
+#if MP_PERL_VERSION_AT_LEAST(5, 9, 3)
     mg->mg_flags |= MGf_LOCAL;
+#endif
 }

 void modperl_env_unload(pTHX)

回答2:

Why are you trying to build your own version of mod_perl? Centos has a pre-built version of mod_perl which will work with the pre-built version of Perl that is already installed.