Error: pip3: command not found in Packer provisioner (exit 127)

Error: pip3: command not found in Packer provisioner (exit status 127)

TL;DR

The guest has Python but no pip. Install it with the system package manager (dnf install python3-pip, apt install python3-pip) before any pip3 commands in your provisioner.

The error

==> virtualbox-iso: /bin/python3: No module named pip
==> virtualbox-iso: /tmp/script_5610.sh: line 6: pip3: command not found
Build 'virtualbox-iso' errored after 5 minutes 14 seconds: Script exited with non-zero exit status: 127. Allowed exit codes are: [0]

Fix it

1. Add the pip install before your pip usage: on RHEL-family dnf install -y python3-pip, on Debian-family apt-get install -y python3-pip.

   • Success check: pip3 --version works on the guest.

2. Do not rely on ensurepip or get-pip.py bootstraps on minimal images; the distro package is more reliable.

   • Success check: the provisioner no longer fails at the pip line.

3. If you need a specific pip version, install the distro pip first, then pip3 install --upgrade pip.

   • Success check: version checks pass.

4. Re-run packer build.

   • Success check: the provisioner completes.

When to use this

You hit this on minimal/base images (Rocky, RHEL, Ubuntu minimal) where Python exists but pip was never installed.

When NOT to use this

Do not use this for No module named [package] after pip install succeeded (that is a package install failure, not a missing pip).

Compatibility

Packer 1.x, shell provisioner, RHEL/Debian-family guests.

Variants

• cannot access /var/lib/alternatives/python: No such file or directory alongside (alternatives not configured on minimal images)
• line N: pip: command not found (same fix, pip vs pip3)

Root cause

Minimal cloud/base images ship Python without pip to stay small. Provisioner scripts that assume pip3 exists fail with exit 127 at the first pip invocation.

Edge cases

• Some images have pip3 but for the wrong Python (e.g. python3.9 vs 3.11). Match the pip to the interpreter your scripts use.
• python3 -m pip works even when the pip3 shim is missing, as a quick workaround.

Asked: how to fix Error: pip3: command not found in Packer provisioner (exit 127). Verified answer: Fixes Packer provisioner scripts failing with 'command not found' for pip3. The fix steps above were cross-checked against the accepted community answer at https://github.com/acavella/packer-rocky9/issues/1, which confirms the same resolution.