Something's up with how the 'speedometer' program is made (the one without the .py extension):

$ ./result/bin/speedometer
Traceback (most recent call last):
  File "/nix/store/rya13rvcr49p2hsnv099143dh7rwam6m-speedometer-2.8/bin/.speedometer-wrapped", line 8, in <module>
    from speedometer import console
  File "/nix/store/rya13rvcr49p2hsnv099143dh7rwam6m-speedometer-2.8/bin/speedometer.py", line 2
    export PATH='/nix/store/6yb5rvr6rvgvx8ylpchwz808djfw07rb-python-2.7.14/bin:/nix/store/rya13rvcr49p2hsnv099143dh7rwam6m-speedometer-2.8/bin:/nix/store/i5ig950zqwln4qi8wfaivgp3bjzzl3jz-python2.7-setuptools-38.2.5/bin'${PATH:+':'}$PATH
              ^
SyntaxError: invalid syntax

Agreed. That happened when I rebased it on top of master, however; it worked perfectly on the installed commit. I'm trying to track it down.

The script is broken by commit d945b3e... somehow.

Two wrapper scripts. One of them works:

#! /nix/store/ski5znw2b8bj5qnsncrcq6128hkrwgvq-bash-4.4-p12/bin/bash -e
export PATH='/nix/store/9n2npaz7xy8b4q0a8k28nr3sjzfy625i-python-2.7.14/bin:/nix/store/jw95yh771yqpqkzwr1f6vkwm2790cknv-speedometer-2.8/bin:/nix/store/vq33bxxy9hyv2cj7w0sxlhg3rj0px0kc-python2.7-setuptools-36.7.1/bin'${PATH:+':'}$PATH
export PYTHONNOUSERSITE='true'
exec -a "$0" "/nix/store/jw95yh771yqpqkzwr1f6vkwm2790cknv-speedometer-2.8/bin/.speedometer-wrapped"  "${extraFlagsArray[@]}" "$@"

And one of them doesn't.

#! /nix/store/nkq0n2m4shlbdvdq0qijib5zyzgmn0vq-bash-4.4-p12/bin/bash -e
export PATH='/nix/store/6yb5rvr6rvgvx8ylpchwz808djfw07rb-python-2.7.14/bin:/nix/store/rya13rvcr49p2hsnv099143dh7rwam6m-speedometer-2.8/bin:/nix/store/i5ig950zqwln4qi8wfaivgp3bjzzl3jz-python2.7-setuptools-38.2.5/bin'${PATH:+':'}$PATH
export PYTHONNOUSERSITE='true'
exec -a "$0" "/nix/store/rya13rvcr49p2hsnv099143dh7rwam6m-speedometer-2.8/bin/.speedometer-wrapped"  "${extraFlagsArray[@]}" "$@"

As far as I can tell, they're identical, but bash fails out at the export PATH.

...wait a second, that's not bash. Why is Python attempting to execute a bash script?

Okay! I think I've figured it out. In short...

Speedometer, upstream, ships with only one meaningful file: speedometer.py, which is what should be packaged as an application. The application is named speedometer. So far, so good, but buildPythonApplication creates two additional files: .speedometer-wrapped and speedometer. The former is a python script wrapping speedometer.py, the latter is a bash script wrapping .speedometer-wrapped.

(At least, I'm assuming that's what does it. Something seems to have parsed speedometer.py in a complex way in order to create it, which is worrying.)

.speedometer-wrapped runs from speedometer import console, and that's where it all goes pear-shaped. Python imports prefer files without extension to .py files, so it attempts to import the bash script, but it prefers .pyc files to everything else -- which is why this worked prior to commit d945b3e.

I don't think name clashes of this sort are uncommon, so probably that commit should be reverted until the bug is fixed. @FRidh, thoughts?

The setup.py is incorrect:

    35     'scripts': ['speedometer.py'],
    36     'entry_points': {
    37         'console_scripts': ['speedometer = speedometer:console'],},

They create a console script even though the file is already marked as to being installed as a script.

Ah, I see. I'll report it upstream. :)

@Baughn are you going to fix this PR or wait for a new release?

Well, I was hoping for a quick fix from the author, but he seems to be AWOL. Not sure what to do now... fork the repo, maybe.

For in here you could remove the console script line.

@GrahamcOfBorg build speedometer

Success on x86_64-linux (full log)

Attempted: speedometer

writing dependency_links to Speedometer.egg-info/dependency_links.txt
reading manifest file 'Speedometer.egg-info/SOURCES.txt'
writing manifest file 'Speedometer.egg-info/SOURCES.txt'
running build_ext

----------------------------------------------------------------------
Ran 0 tests in 0.000s

OK
/nix/store/3hajywdmsclsz62v3m1yk875pdxinlpk-speedometer-2.8

Success on aarch64-linux (full log)

Attempted: speedometer

writing dependency_links to Speedometer.egg-info/dependency_links.txt
reading manifest file 'Speedometer.egg-info/SOURCES.txt'
writing manifest file 'Speedometer.egg-info/SOURCES.txt'
running build_ext

----------------------------------------------------------------------
Ran 0 tests in 0.000s

OK
/nix/store/0qs8pc83wln5m8vrqdk77a2a63g4br0d-speedometer-2.8