Docker How to debug when docker build fails
Introduction
When a
docker build -t mytag . fails with a message such as ---> Running in d9a42e53eb5a The command '/bin/sh -c returned a non-zero code: 127 (127 means "command not found, but 1) it is not trivial for everybody 2) 127 may be replaced by 6 or anything) it may be non trivial to find the error in a long line
