pyperformance run --python= argument doesn't work on Windows

[Fidget-Spinner]

Steps to reproduce:

> pyperformance run --python="C:\User\GitHub\cpython\PCbuild\amd64\python.exe"
Creating the virtual environment venv\cpython3.10-3bfab7affa2d
...
... <installing packages>
...
INFO:root:Running `C:\User\GitHub\cpython\PCbuild\amd64\python.exe -u D:\User\Downloads\python\venv\cpython3.10-3bfab7affa2d\Lib\site-packages\pyperformance\benchmarks\bm_xml_etree.py --output C:\Users\User\AppData\Local\Temp\tmpo_57rqul`
Traceback (most recent call last):
  File "D:\User\Downloads\python\venv\cpython3.10-3bfab7affa2d\Lib\site-packages\pyperformance\benchmarks\bm_xml_etree.py", line 17, in <module>
    import pyperf
ModuleNotFoundError: No module named 'pyperf'
ERROR: Benchmark xml_etree failed: Benchmark died
Traceback ...
RuntimeError: Benchmark died

For some reason, pyperformance runs the benchmark by calling C:\User\GitHub\cpython\PCbuild\amd64\python.exe. I think it should be calling the venv's python (venv\cpython3.10-3bfab7affa2d\Scripts\python.exe) instead.

[brettcannon]

This isn't Windows-specific I have it under Linux as well:

ERROR: Benchmark xml_etree failed: Benchmark died
Traceback (most recent call last):
  File "/tmp/venv/cpython3.8-abf70bc4132b/lib/python3.8/site-packages/pyperformance/run.py", line 130, in run_benchmarks    bench = func(cmd_prefix, options)
  File "/tmp/venv/cpython3.8-abf70bc4132b/lib/python3.8/site-packages/pyperformance/benchmarks/__init__.py", line 152, in BM_xml_etree
    return run_perf_script(python, options, "xml_etree")
  File "/tmp/venv/cpython3.8-abf70bc4132b/lib/python3.8/site-packages/pyperformance/run.py", line 96, in run_perf_script    run_command(cmd, hide_stderr=not options.verbose)
  File "/tmp/venv/cpython3.8-abf70bc4132b/lib/python3.8/site-packages/pyperformance/run.py", line 64, in run_command
    raise RuntimeError("Benchmark died")
RuntimeError: Benchmark died

ERROR: No benchmark was run

If the solution suggested by @Fidget-Spinner doesn't fix it then maybe setting PYTHONPATH to include pyperf has shipped with pyperformance could deal with the problem. But otherwise right now you can't install pyperformance via e.g. pipx and use it to run the benchmark suite.

[ericsnowcurrently]

fix: #169