The original purpose was a way to build io.js for centos 6 repeatably using:

docker run --rm -v ${WORKSPACE}:/iojs -w /iojs -t devtoolset-3 ./tools/rpm/rpmbuild.sh

Based on:

https://github.com/sclorg/rhscl-dockerfiles/tree/master/centos6.devtoolset-3-toolchain

To build the Dockerfile, run:

# docker build -t devtoolset-3 .

Run docker run THIS_IMAGE container-usage to get this help.

Run docker run -ti THIS_IMAGE bash to obtain interactive shell.

Run docker exec -ti CONTAINERID container-entrypoint to access already running container.

In order to get the container ID after running the image, pass --cidfile= option to the docker run command. That will instruct Docker to write a file with the container ID.

You may try -e CONT_DEBUG=VAL with VAL up to 3 to get more verbose debugging info.