Building / Installation from source fails, due to a wrong use of pathlib in python scripts. Luckily, the fix is simple.


STEPS TO REPRODUCE

1. have in python3 pathlib and pathlib2 installed

2. download breeze-icons-5.85.0 tarball

3. follow the usual build instructions:

mkdir build
cd build
cmake \
-DCMAKE_INSTALL_PREFIX=/opt/kf5 
-DCMAKE_PREFIX_PATH=/opt/qt5 \
-DCMAKE_BUILD_TYPE=Release \
-DBUILD_TESTING=OFF \
-Wno-dev ..

4. make install


OBSERVED RESULT

...
[ 45%] Generating 24px icons-dark
Traceback (most recent call last):
  File "/Sources/breeze-icons-5.85.0/generate-24px-versions.py", line 170, in <module>
    sys.exit(main())
  File "/Sources/breeze-icons-5.85.0/generate-24px-versions.py", line 76, in main
    Path(folder24_destination).mkdir(parents=True, exist_ok=True)
TypeError: mkdir() got an unexpected keyword argument 'exist_ok'
...


EXPECTED RESULT

...
[  9%] Automatic MOC for target qrcAlias
[  9%] Built target qrcAlias_autogen
[ 36%] Built target qrcAlias
[ 45%] Generating 24px icons-dark
mimetypes/22/text-x-lua.svg SKIPPED: not square or incorrect viewBox
viewBox="0 0 16 16"
mimetypes/22/text-x-go.svg SKIPPED: not square or incorrect viewBox
viewBox="0 0 16 16"
...
[ 90%] Generating res/breeze-icons-dark.qrc
[100%] Generating breeze-icons-dark.rcc
[100%] Built target breeze-icons-dark-rcc


SOFTWARE/OS VERSIONS

Linux/KDE Plasma: self-built Linux with recent Kernel, Programs and Libraries
KDE Plasma Version: not yet installed
KDE Frameworks Version: 5.85.0
Qt Version: 5.15.2


ADDITIONAL INFORMATION

> command -v python3

/usr/bin/python3

> ls -1 /usr/lib/python3.9/site-packages/

...
netaddr-0.8.0-py3.9.egg
networkx-2.6.2-py3.9.egg
numpy-1.21.2-py3.9-linux-x86_64.egg
packaging-21.0-py3.9.egg
pathlib-1.0.1-py3.9.egg-info
pathlib2-2.3.6-py3.9.egg
pathlib.py
pathtools-0.1.2-py3.9.egg
pbr
pbr-5.6.0-py3.9.egg-info
pep8-1.7.1-py3.9.egg
...


As you can see, pathlib and pathlib2 are installed (for various reasons). Anyway, changing the python script in question

breeze-icons-5.85.0/generate-24px-versions.py :

"from pathlib import Path"  ->  "from pathlib2 import Path"

fixes this problem (at least for me).