[DOC] Add --no-binary to reinstall command

[lopuhin]

Without this option pillow-simd will not be recompiled if it is already installed. Adding --no-binary pillow-simd forces the recompile.

I'm not sure if this is the correct branch, contributors guide says to make PRs to master, but I don't see a master branch in the repo.

[homm]

Could you describe the case more precisely? I'm trying the following:

$ pip uninstall pillow
Cannot uninstall requirement pillow, not installed

$ pip uninstall pillow-simd
Cannot uninstall requirement pillow-simd, not installed

$ pip install pillow-simd
Collecting pillow-simd
  Using cached Pillow-SIMD-5.1.1.post0.tar.gz
Installing collected packages: pillow-simd
  Running setup.py install for pillow-simd ... done
Successfully installed pillow-simd-5.1.1.post0

$ ./run.py scale
Scale 2560×1600 RGB image
    to 26x16 bil        0.00347 s  1181.07 Mpx/s
    to 26x16 bic        0.00666 s   614.84 Mpx/s
    to 26x16 lzs        0.01033 s   396.55 Mpx/s
    to 320x200 bil      0.00479 s   855.87 Mpx/s
    to 320x200 bic      0.00758 s   540.59 Mpx/s
    to 320x200 lzs      0.01271 s   322.27 Mpx/s
    to 2048x1280 bil    0.01488 s   275.21 Mpx/s
    to 2048x1280 bic    0.02163 s   189.34 Mpx/s
    to 2048x1280 lzs    0.02927 s   139.94 Mpx/s
    to 5478x3424 bil    0.07110 s    57.61 Mpx/s
    to 5478x3424 bic    0.09565 s    42.82 Mpx/s
    to 5478x3424 lzs    0.13172 s    31.10 Mpx/s

$ CC="cc -mavx2" pip install -U --force-reinstall pillow-simd
Collecting pillow-simd
  Using cached Pillow-SIMD-5.1.1.post0.tar.gz
Installing collected packages: pillow-simd
  Found existing installation: Pillow-SIMD 5.1.1.post0
    Uninstalling Pillow-SIMD-5.1.1.post0:
      Successfully uninstalled Pillow-SIMD-5.1.1.post0
  Running setup.py install for pillow-simd ... done
Successfully installed pillow-simd-5.1.1.post0

$ ./run.py scale
Scale 2560×1600 RGB image
    to 26x16 bil        0.00270 s  1518.73 Mpx/s
    to 26x16 bic        0.00457 s   896.65 Mpx/s
    to 26x16 lzs        0.00720 s   568.89 Mpx/s
    to 320x200 bil      0.00344 s  1189.00 Mpx/s
    to 320x200 bic      0.00573 s   715.08 Mpx/s
    to 320x200 lzs      0.00905 s   452.75 Mpx/s
    to 2048x1280 bil    0.01281 s   319.63 Mpx/s
    to 2048x1280 bic    0.01638 s   250.09 Mpx/s
    to 2048x1280 lzs    0.02355 s   173.91 Mpx/s
    to 5478x3424 bil    0.05099 s    80.32 Mpx/s
    to 5478x3424 bic    0.06853 s    59.77 Mpx/s
    to 5478x3424 lzs    0.09499 s    43.12 Mpx/s

As you can see, recompilation works.

[lopuhin]

@homm I see, thanks for checking this. For me, the output of the reinstall command is slightly different:

CC="ccfasdfad -mavx2" pip install -U --force-reinstall pillow-simd
Collecting pillow-simd
Installing collected packages: pillow-simd
  Found existing installation: Pillow-SIMD 5.1.1.post0
    Uninstalling Pillow-SIMD-5.1.1.post0:
      Successfully uninstalled Pillow-SIMD-5.1.1.post0
Successfully installed pillow-simd-5.1.1.post0

As you can see, it does not have Running setup.py install for pillow-simd ... done and also it succeeds despite using a bogus CC value.

I think the reason for this is the following, here is the output of the first pip install command:

pip install -U --force-reinstall pillow-simd
Collecting pillow-simd
  Downloading Pillow-SIMD-5.1.1.post0.tar.gz (14.2MB)
    100% |████████████████████████████████| 14.2MB 103kB/s
Building wheels for collected packages: pillow-simd
  Running setup.py bdist_wheel for pillow-simd ... done
  Stored in directory: /Users/kostia/Library/Caches/pip/wheels/58/45/cf/aaf3e1db66c24e3350e3a2ad9bd6dfbd574ede6d613ba321bf
Successfully built pillow-simd
Installing collected packages: pillow-simd
Successfully installed pillow-simd-5.1.1.post0

As you can see, the wheel is cached ( Stored in directory: /Users/kostia/Library/Caches/pip/wheels/58/45/cf/aaf3e1db66c24e3350e3a2ad9bd6dfbd574ede6d613ba321bf) and this wheel is re-used on re-installation, unless --no-binary is passed. This cache is on by default in pip I think: https://pip.pypa.io/en/stable/reference/pip_install/#caching

[Globegitter]

I had to do the same as @lopuhin reported - only with adding the no-binary flag it recompiles properly and the performance tests improve significantly.