Specify particular Perl path to a module during installation

[Technext]

I am trying to install DBD-mysql-4.022 on RHEL5 2.6.18-194.el5 box. I have two versions of Perl on the given box (5.8.8 - default & 5.16.1)

Installation of DBD-mysql-4.022 failed with the following error:

#     Error:  Can't load '/root/.cpan/build/DBD-mysql-4.022/blib/arch/
+auto/DBD/mysql/mysql.so' for module DBD::mysql: /root/.cpan/build/DBD
+-mysql-4.022/blib/arch/auto/DBD/mysql/mysql.so: undefined symbol: mys
+ql_get_server_version at /usr/lib64/perl5/5.8.8/x86_64-linux-thread-m
+ulti/DynaLoader.pm line 230.

I found that this can be fixed by specifying path to libmysqlclient.a

Ref: http://cpansearch.perl.org/src/JWIED/DBD-mysql-2.1012/INSTALL.html#known%20problems

[root@RHEL5 DBD-mysql-4.022]# perl Makefile.PL --libs='/usr/lib64/mysq
+l/libmysqlclient.a'

PLEASE NOTE:
For 'make test' to run properly, you must ensure that the
database user 'root' can connect to your MySQL server
and has the proper privileges that these tests require such
as 'drop table', 'create table', 'drop procedure', 'create procedure'
as well as others.

mysql> grant all privileges on test.* to 'root'@'localhost' identified
+ by 's3kr1t';

You can also optionally set the user to run 'make test' with:

perl Makefile.PL --testuser=username

I will use the following settings for compiling and testing:

  cflags        (mysql_config ) = -I/usr/include/mysql -g -pipe -Wp,-D
+_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-s
+ize=4 -m64 -fPIC -g -static-libgcc -fno-omit-frame-pointer -fno-stric
+t-aliasing -DMY_PTHREAD_FASTMUTEX=1
  embedded      (mysql_config ) =
  libs          (User's choice) = /usr/lib64/mysql/libmysqlclient.a
  mysql_config  (guessed      ) = mysql_config
  nocatchstderr (default      ) = 0
  nofoundrows   (default      ) = 0
  ssl           (guessed      ) = 0
  testdb        (default      ) = test
  testhost      (default      ) =
  testpassword  (default      ) =
  testsocket    (default      ) =
  testuser      (guessed      ) = root

To change these settings, see 'perl Makefile.PL --help' and
'perldoc INSTALL'.

Checking if your kit is complete...
Looks good
Unrecognized argument in LIBS ignored: '/usr/lib64/mysql/libmysqlclien
+t.a'
Multiple copies of Driver.xst found in: /usr/lib64/perl5/site_perl/5.8
+.8/x86_64-linux-thread-multi/auto/DBI/ /usr/lib64/perl5/vendor_perl/5
+.8.8/x86_64-linux-thread-multi/auto/DBI/ at Makefile.PL line 941
Using DBI 1.622 (for perl 5.008008 on x86_64-linux-thread-multi) insta
+lled in /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/au
+to/DBI/
Writing Makefile for DBD::mysql
Writing MYMETA.yml and MYMETA.json

As we can see above, DBD-mysql is referring to the default (5.8.8) perl. I am not sure how to tell Makefile.pl to refer the latest installed perl i.e., 5.16.1. I saw that the Makefile.pl has the following entry to find the perl installation:

use Config;
exec ($Config{perlpath}, $0, @ARGV )|| die $!;

Now i know that if i prepend my latest (5.16.1) perl installation path to the variable PATH, it might work but my concern is that later if i revert the settings in PATH, then will DBD-mysql still use Perl version 5.16.1? I am asking this mainly because i don't want to disturb the existing PATH settings for applications that require Perl 5.8.8 and at the same time want to ensure that DBD-mysql always refers the latest perl i.e., 5.16.1.

Also, how can i undo what i have done by using perl Makefile.PL --libs='/usr/lib64/mysql/libmysqlclient.a' just to make sure that everything is clean?

[space_monk]

AFAIK, as long as the PATH points to the right PERL, the rest should follow on naturally. You might want to set PERL5LIB too.

You shouldn't revert the path; any program that uses your 5.16.1 version should have the correct environment to run in.

Your program can of course check which version it is running by means of a use 5.16.1;

Someone correct me if I've got any of the above wrong :-)

[CountZero]

Could it be that when you run perl Makefile.PL you run the default Perl? You could edit the Makefile.PL to point to your perl 5.16.1.

[space_monk]

I don't think you have to edit Makefile.PL at all as long as you are sure the PATH environment variable points to the 5.16.1 version of perl first before you build the module. Just do perl -v from the command line before running Makefile.PL to make sure.

[CountZero]

True, but many programs and services on your computer may rely on the "system" Perl to do their jobs. Switching wholesale to a newer Perl may very well cause all kinds of havoc that will be difficult to trace. I'd rather not mess around with such global options, unless there is absolutely no other solution available.