error: subprocess-exited-with-error - What did I wrong?

[Steph6431]

I just ried to install but received the following error:

➜ smartCharge4evcc git:(main) pip install -r requirements.txt
Looking in indexes: https://pypi.org/simple, https://wheels.home-assistant.io/musllinux-index/
Collecting flask (from -r requirements.txt (line 1))
Downloading https://wheels.home-assistant.io/musllinux-index/flask-3.1.0-py3-none-any.whl (102 kB)
Collecting paho-mqtt (from -r requirements.txt (line 2))
Downloading https://wheels.home-assistant.io/musllinux-index/paho_mqtt-2.1.0-py3-none-any.whl (67 kB)
Collecting influxdb-client (from -r requirements.txt (line 3))
Downloading influxdb_client-1.48.0-py3-none-any.whl.metadata (65 kB)
Collecting numpy (from -r requirements.txt (line 4))
Downloading https://wheels.home-assistant.io/musllinux-index/numpy-2.2.3-cp312-cp312-musllinux_1_2_x86_64.whl (17.9 MB)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 17.9/17.9 MB 1.5 MB/s eta 0:00:00
Collecting pandas (from -r requirements.txt (line 5))
Downloading https://wheels.home-assistant.io/musllinux-index/pandas-2.2.3-cp312-cp312-musllinux_1_2_x86_64.whl (14.1 MB)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 14.1/14.1 MB 1.5 MB/s eta 0:00:00
Collecting requests (from -r requirements.txt (line 6))
Downloading https://wheels.home-assistant.io/musllinux-index/requests-2.32.3-py3-none-any.whl (64 kB)
Collecting scipy (from -r requirements.txt (line 7))
Downloading scipy-1.15.2-cp312-cp312-musllinux_1_2_x86_64.whl.metadata (61 kB)
Collecting scikit-learn (from -r requirements.txt (line 8))
Downloading scikit_learn-1.6.1.tar.gz (7.1 MB)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 7.1/7.1 MB 1.4 MB/s eta 0:00:00
Installing build dependencies ... done
Getting requirements to build wheel ... done
Installing backend dependencies ... done
Preparing metadata (pyproject.toml) ... error
error: subprocess-exited-with-error

× Preparing metadata (pyproject.toml) did not run successfully.
│ exit code: 1
╰─> [2 lines of output]

  meson-python: error: Could not find ninja version 1.8.2 or newer.
  [end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.

[Coernel82]

I cannot really help you on this. What I can see is that you try to install the packages from a home assistant server - maybe there are incompatibilities. I just consulted github Co-Pilot which came up with some useful ideas. Maybe you do the same and then post the solution here. I will then update the readme with troubleshooting!
I was able to install scikit-learn without problems.