`Cannot get Docker version` when using rootless/master version of docker

[danwdart]

Steps to reproduce

For example:

1. Install rootless docker via official instructions curl -sSL https://get.docker.com/rootless | sh
2. Observe output from command docker --version, e.g.: Docker version master-dockerproject-2019-07-12, build 6fc0dc91
3. Run command stack --docker ls dependencies.
4. Observe result Cannot get Docker version (invalid 'docker --version' output).

Expected

The version of Docker detected by Stack is displayed.

Actual

$ stack --verbose --docker ls dependencies 
Version 2.1.3, Git revision 636e3a759d51127df2b62f90772def126cdf6d1f (7735 commits) x86_64 hpack-0.31.2
2019-11-15 10:39:22.583156: [debug] Checking for project config at: /home/dwd/code/other/metasploit-framework/stack.yaml
2019-11-15 10:39:22.583309: [debug] Checking for project config at: /home/dwd/code/other/stack.yaml
2019-11-15 10:39:22.583370: [debug] Checking for project config at: /home/dwd/code/stack.yaml
2019-11-15 10:39:22.583427: [debug] Checking for project config at: /home/dwd/stack.yaml
2019-11-15 10:39:22.583488: [debug] Checking for project config at: /home/stack.yaml
2019-11-15 10:39:22.583535: [debug] Checking for project config at: /stack.yaml
2019-11-15 10:39:22.583577: [debug] No project config file found, using defaults.
2019-11-15 10:39:22.590005: [debug] SELECT COUNT(*) FROM "last_performed" WHERE ("action"=?) AND ("timestamp">=?); [PersistInt64 1,PersistUTCTime 2019-11-14 10:39:22.589967368 UTC]
2019-11-15 10:39:22.590500: [debug] Run process: /home/dwd/bin/docker --version
2019-11-15 10:39:22.626097: [debug] Process finished in 36ms: /home/dwd/bin/docker --version
2019-11-15 10:39:22.626311: [error] Cannot get Docker version (invalid 'docker --version' output).

$ stack --version
Version 2.1.3, Git revision 636e3a759d51127df2b62f90772def126cdf6d1f (7735 commits) x86_64 hpack-0.31.2

Method of installation

Official binary, downloaded from stackage.org

[mpilgrem]

Stack expects and requires that the output of docker --version will have the form:

<word> <word> <raw-version> <word> [<words>]

where <raw-version> has the form

<dotted-version><discarded-stuff>

and <discarded-stuff> is either all non-digits or starts with -.

That seems to me to be consistent with the tags at https://github.com/docker/cli/tags, which go back to 17.07.0-ce-rc1 and May 2017.

Docker version master-dockerproject-2019-07-12, build 6fc0dc91, clearly, does not have that form. I do not know if that is systematic or an exeception (a mistake, perhaps).