Dockerfile RUN pip install exit code 1 in CI

By Kaveh Alemi·Latchkey

pip exited non-zero inside a RUN step, so the whole build step fails with exit code 1. The real reason is in the pip output above the summary line: usually no network to PyPI, or a source build that needs a compiler the image lacks.

What this error means

A RUN pip install step ends with "process \"/bin/sh -c pip install -r requirements.txt\" did not complete successfully: exit code: 1" after pip prints a network or build error.

ERROR: failed to solve: process "/bin/sh -c pip install -r requirements.txt"
did not complete successfully: exit code: 1

Common causes

No egress or proxy for PyPI inside the build

The build network cannot reach PyPI, so pip fails with a name-resolution or timeout error and exits 1.

A source build with no compiler or headers

A package with no wheel for the platform compiles from source and needs build tools or -dev headers a slim image does not include.

How to fix it

Add the build dependencies pip needs

Install a compiler and headers before pip when a source build is unavoidable.

RUN apt-get update \
 && apt-get install -y --no-install-recommends build-essential python3-dev \
 && rm -rf /var/lib/apt/lists/*
RUN pip install --no-cache-dir -r requirements.txt

Configure the index or prefer wheels

1. Point pip at an internal mirror with PIP_INDEX_URL when egress is restricted.
2. Force binary wheels so no compiler is needed where possible.
3. Ensure the build has DNS and egress to the index.

RUN pip install --only-binary=:all: -r requirements.txt

How to prevent it

• Give the build network access to the package index it needs.
• Install -dev packages and a compiler for unavoidable source builds.
• Prefer wheels so the build never invokes a compiler.

Frequently asked questions

Related guides

References

• Docker documentation
• Docker build cache
• GitHub Actions documentation