failed to solve: process "/bin/sh -c ..." did not complete successfully: exit code: 1 — how to fix

ERROR: failed to solve: process "/bin/sh -c npm install" did not complete successfully: exit code: 1
ERROR: failed to solve: process "/bin/sh -c apt-get install -y libpq-dev" did not complete successfully: exit code: 100
ERROR: failed to solve: process "/bin/sh -c pip install -r requirements.txt" did not complete successfully: exit code: 1

Quick fix: Scroll up to the failing step's own output (or rebuild with docker build --progress=plain --no-cache .) and fix that error. Common ones: run apt-get update in the same RUN as apt-get install -y, copy package-lock.json/requirements.txt before installing, use a base image with the needed tools, and check the command exists in slim/alpine images.

What it means

Each RUN line runs a shell command inside the build container. If it exits with anything but 0, the build fails with this generic message. The message only tells you which command failed and its exit code; the reason is in that command's output just above.

Get the full output, uncollapsed and uncached:

docker build --progress=plain --no-cache -t myapp . 2>&1 | tee build.log

The exit code is a hint:

Code	Usually means
1	the tool itself failed (npm/pip/compiler error)
2	misuse / make error
100	apt-get failed (package not found, stale index)
127	command not found in the image
137	killed, usually out of memory

Cause 1: apt-get (exit code 100)

E: Unable to locate package or 404s happen when the package index is missing or cached from an old layer. Always update and install in the same RUN:

RUN apt-get update && apt-get install -y --no-install-recommends \
        build-essential libpq-dev \
    && rm -rf /var/lib/apt/lists/*

Check the package name exists for the base image's distro version (Debian names differ from Ubuntu sometimes). On Alpine use apk add --no-cache ... instead.

Cause 2: command not found (exit code 127)

Slim and Alpine images lack many tools (curl, git, bash, make, gcc). Install them first, or pick a fuller base image. Alpine has no bash by default; use sh or apk add bash.

Cause 3: npm install / npm ci fails

npm ci requires package-lock.json. Copy it before installing:

COPY package.json package-lock.json ./
RUN npm ci
COPY . .

Native modules (node-gyp, bcrypt, sharp) need build tools: apk add --no-cache python3 make g++ on Alpine.
ERESOLVE peer dependency errors: fix the dependency, or npm ci --legacy-peer-deps as a stopgap.
Add node_modules to .dockerignore so your host's modules don't get copied over.

Cause 4: pip install fails

Failed building wheel on slim/alpine: install compilers and headers (gcc, python3-dev/musl-dev, libpq-dev), or use the non-Alpine python:3.x-slim where most packages have prebuilt wheels.
A pinned version not available for that Python version: match the base image's Python to what your requirements support.

Cause 5: killed for memory (exit code 137)

Builds of large frontends or compiled languages can exhaust Docker's memory. Increase memory in Docker Desktop settings, or limit the tool (NODE_OPTIONS=--max-old-space-size=4096, cargo build -j 2).

Cause 6: wrong architecture

Building an amd64 image on Apple Silicon (or vice versa) can make downloaded binaries fail with exec format error. Set the platform explicitly: docker build --platform linux/amd64 .

Debugging tip

Comment out the failing RUN and everything after it, build, then open a shell in that image and run the command by hand:

docker build -t debug .
docker run --rm -it debug sh

Last updated 2026-11-01.