Re: "symbol lookup error" message help

How do I specify which version of perl is being used when I install a module using cpanm?

You should have two cpanm, one installed with each perl. They will have different shebang (#!) lines.

It's simply a question of using the right cpanm (e.g. by using its full path to launch it).

head -n 1 /tool/bin/cpanm       # #!/tool/bin/perl
/tool/bin/cpanm Some::Module    # Installs for /tool/bin/perl
[download]

The cpanm script itself should work with any perl, so you could explicitly specify the perl to use as a fallback.

/tool/bin/perl "$( which cpanm )" Some::Module
[download]

Why do the new modules I installed to /new_location/perl_modules/5.20/lib/perl5 work for both /tool/bin/perl (v5.20.0) and /usr/bin/perl (v5.26.3)

There's no guarantee that using different build will fail.

There's merely no effort made to ensure that it won't fail.

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Re^2: "symbol lookup error" message help by Special_K (Monk) on Jan 28, 2023 at 17:49 UTC
Given a directory where perl modules are already installed (ex: `/home/user_foo/perl_modules/lib/perl5` from my original message), how do I determine what version of perl was used to install them?	[reply] [d/l]
Re^3: "symbol lookup error" message help by Anonymous Monk on Feb 01, 2023 at 05:54 UTC
Use Module::Metadata (core) to examine the path: `/usr/bin/perl -MModule::Metadata -le 'print Module::Metadata->find_mod +ule_by_name("Class::Struct")'` [download] `/System/Library/Perl/5.18/Class/Struct.pm`	[reply] [d/l]
Re^4: "symbol lookup error" message help by Special_K (Monk) on Feb 03, 2023 at 20:10 UTC
That gives me the path to a module I specify by name, but that's not what I'm asking. I'm asking: given a directory where 1 or more perl modules are installed (ex: `/home/user_foo/perl_modules/lib/perl5` from my original message), is there a way to determine what version of perl (e.g. 5.12.2, 5.16.3, etc.) was used to install those modules?	[reply] [d/l]
Re^5: "symbol lookup error" message help by afoken (Chancellor) on Feb 04, 2023 at 10:40 UTC
Re^2: "symbol lookup error" message help by Special_K (Monk) on Feb 03, 2023 at 21:14 UTC
> There's no guarantee that using different build will fail. > There's merely no effort made to ensure that it won't fail. So is the best practice to just have a complete modules directory corresponding to each version of installed perl, no matter how minor the version update? For example, if I have the following (hypothetical) versions installed: `5.26.1 5.26.2 5.26.3 5.26.4` [download] Then each one of those should have its own complete modules directory?	[reply] [d/l]
Re^3: "symbol lookup error" message help by Corion (Patriarch) on Feb 03, 2023 at 21:32 UTC
Perl actually guarantees that you can upgrade between minor versions without needing to recompile. But that implies that the new minor version was compiled with exactly the same compiler and compiler options as the old one.	[reply]
Re^2: "symbol lookup error" message help by Special_K (Monk) on Feb 03, 2023 at 21:52 UTC
Here's what I don't understand: I ran the following: `> which cpanm /bin/cpanm > head -n 1 /bin/cpanm #!/usr/bin/perl` [download] I know that `/usr/bin/perl` on this machine is `5.26.3`, yet if I look at the most recent cpanm `build.log` file, it says: `cpanm (App::cpanminus) 1.7044 on perl 5.026003 built for x86_64-linux- +thread-multi` [download] Why does the log file list perl version `5.026003` when `/usr/bin/perl` is `5.26.3`?	[reply] [d/l] [select]
Re^3: "symbol lookup error" message help by Corion (Patriarch) on Feb 03, 2023 at 22:02 UTC
Because `$]`, the variable containing the Perl version number has the value `5.026003`. See the documentation in perlvar.	[reply] [d/l] [select]
Re^3: "symbol lookup error" message help by ikegami (Patriarch) on Feb 05, 2023 at 19:23 UTC
5.026003 is 5.26.3. `5.026003 \|_\|\|_\| 26 3` [download]	[reply] [d/l]
Re^3: "symbol lookup error" message help by Anonymous Monk on Feb 05, 2023 at 19:37 UTC
See "perldoc version" (version on the CPAN). `perl -le 'print $]'` [download] 5.026003 `perl -le 'print $^V'` [download] v5.26.3 `perl -Mversion -le 'print version->parse("5.026003")->normal'` [download] v5.26.3 `perl -Mversion -le 'print version->declare("v5.26.3")->numify'` [download] 5.026003	[reply] [d/l] [select]


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