Perl "Can't locate ExtUtils/MakeMaker.pm" in CI

By Kaveh Alemi·Latchkey

Makefile.PL starts with use ExtUtils::MakeMaker; and the runner Perl does not have it on @INC. It normally ships in core, so this points to a stripped or custom interpreter.

What this error means

The configure step dies immediately with "Can't locate ExtUtils/MakeMaker.pm in @INC" at line 1 of Makefile.PL.

Can't locate ExtUtils/MakeMaker.pm in @INC (you may need to install the
ExtUtils::MakeMaker module) (@INC contains: /home/runner/perl5/lib/perl5 .)
at Makefile.PL line 1.

Common causes

A minimal Perl missing core toolchain modules

A slim image or an isolated local::lib omits ExtUtils::MakeMaker, which most distributions need at configure time.

A very old or hand-built Perl

A custom-compiled Perl that skipped the toolchain leaves MakeMaker unavailable for building from source.

How to fix it

Install the MakeMaker toolchain

Install ExtUtils::MakeMaker (and Module::Build for Build.PL distributions) before configuring.

cpanm --notest ExtUtils::MakeMaker Module::Build

Use a full Perl via setup-perl

A standard Perl provisioned by the setup action ships the toolchain, so MakeMaker is present.

- uses: shogo82148/actions-setup-perl@v1
  with:
    perl-version: '5.38'

How to prevent it

• Provision a standard Perl that includes the core toolchain.
• Install ExtUtils::MakeMaker and Module::Build into isolated local::libs.
• Avoid stripping toolchain modules from custom images.

Frequently asked questions

Related guides

References

• GitHub Actions documentation