Historically, the `/bin` directory on Unix has a reduced set of
commands used for small mounts while booting the system. As such,
it is common for `/bin` to be missing the `env` command.
For the same historical reasons, `/usr/bin` tends to have most if
not all commands provided to the user environment. Thus,
`/usr/bin/env` is more likely to exist than `/bin/env`. This is
in fact the case for Mac OSX, which is a very widely used version
of *nix.
Thus, it is better to use `#!/usr/bin/env` as the hash-bang in
scripts.
Previously stages like `doxygen` wouldn't be detected by
reproduce_ci_env as they didn't start with `build:` or `test:`.
Now we properly look for the `stage` key.
To simplify reproducing docker based CI workers locally, VTK-m has python program that handles all the
work automatically for you.
The program is located in `[Utilities/CI/reproduce_ci_env.py ]` and requires python3 and pyyaml.
To use the program is really easy! The following two commands will create the `build:rhel8` gitlab-ci
worker as a docker image and setup a container just as how gitlab-ci would be before the actual
compilation of VTK-m. Instead of doing the compilation, instead you will be given an interactive shell.
```
./reproduce_ci_env.py create rhel8
./reproduce_ci_env.py run rhel8
```
To compile VTK-m from the the interactive shell you would do the following:
```
> src]# cd build/
> build]# cmake --build .
```
