Repository: python-pillow/Pillow

Issue:
Cygwin64 compatibility
I'm trying to install Pillow in a virtualenv on cygwin64 (all packages up to date) with python3.
command: `pip install Pillow`
I have checked all the dependencies, and I've tried the rebaseall solution. I've tried it on two different machines, one with anti-virus and one without.

I end up getting a bunch of errors like this:
`0 [main] python3 9732 fork: child -1 - forked process 8204 died unexpectedly, retry 0, exit code 0xC0000005, errno 11`
Pillow is the only package I've had issues installing.

I'm wiling to help hunt the problem down. Just need some help heading in the right direction.



Discussion:
Please can you post the full error trace?

I don't know what's causing that, but for what it's worth, it works with a MINGW64 shell (from Git Bash) and Python 2.7.9:

```
$ pip install pillow
Collecting pillow
  Using cached Pillow-3.1.0-cp27-none-win_amd64.whl
Installing collected packages: pillow
Successfully installed pillow-3.1.0
```

Working in a clean virtualenv, python 3.4.3, cygwin64, pip 8.0.2

`$ pip install Pillow &> Pillow-Failure.txt`

Pillow-Failure.txt:

```
$ pip install Pillow
Collecting Pillow
  Using cached Pillow-3.1.0.tar.gz
Installing collected packages: Pillow
  Running setup.py install for Pillow ... error
    Complete output from command /cygdrive/c/Users/s7726/.virtualenvs/pillowtest/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-g3f24mpy/Pillow/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-20r5d54m-record/install-record.txt --single-version-externally-managed --compile --install-headers /cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include/site/python3.4/Pillow:
    running install
    running build
    running build_py
    creating build
    creating build/lib.cygwin-2.4.1-x86_64-3.4
    creating build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/BdfFontFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/BmpImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/BufrStubImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ContainerIO.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/CurImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/DcxImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/EpsImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ExifTags.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/features.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/FitsStubImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/FliImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/FontFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/FpxImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/GbrImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/GdImageFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/GifImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/GimpGradientFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/GimpPaletteFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/GribStubImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/Hdf5StubImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/IcnsImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/IcoImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/Image.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageChops.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageCms.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageColor.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageDraw.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageDraw2.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageEnhance.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageFilter.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageFont.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageGrab.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageMath.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageMode.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageMorph.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageOps.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImagePalette.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImagePath.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageQt.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageSequence.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageShow.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageStat.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageTk.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageTransform.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImageWin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/ImtImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/IptcImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/Jpeg2KImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/JpegImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/JpegPresets.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/McIdasImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/MicImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/MpegImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/MpoImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/MspImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/OleFileIO.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PaletteFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PalmImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PcdImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PcfFontFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PcxImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PdfImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PixarImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PngImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PpmImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PsdImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PSDraw.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/PyAccess.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/SgiImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/SpiderImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/SunImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/TarIO.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/TgaImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/TiffImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/TiffTags.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/WalImageFile.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/WebPImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/WmfImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/XbmImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/XpmImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/XVThumbImagePlugin.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/_binary.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/_util.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    copying PIL/__init__.py -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    running egg_info
    writing top-level names to Pillow.egg-info/top_level.txt
    writing Pillow.egg-info/PKG-INFO
    writing dependency_links to Pillow.egg-info/dependency_links.txt
    warning: manifest_maker: standard file '-c' not found

    reading manifest file 'Pillow.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    warning: no previously-included files found matching '.editorconfig'
    writing manifest file 'Pillow.egg-info/SOURCES.txt'
    copying PIL/OleFileIO-README.md -> build/lib.cygwin-2.4.1-x86_64-3.4/PIL
    running build_ext
    building 'PIL._imaging' extension
    creating build/temp.cygwin-2.4.1-x86_64-3.4
    creating build/temp.cygwin-2.4.1-x86_64-3.4/libImaging
    Building using 4 processes
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c _imaging.c -o build/temp.cygwin-2.4.1-x86_64-3.4/_imaging.o
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c libImaging/Resample.c -o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Resample.o
          0 [main] python3 14316 fork: child -1 - forked process 9672 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
          0 [main] python3 1816 fork: child -1 - forked process 13988 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c libImaging/Crop.c -o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Crop.o
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c libImaging/Geometry.c -o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Geometry.o
     307919 [main] python3 1816 fork: child -1 - forked process 9828 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
     308169 [main] python3 14316 fork: child -1 - forked process 13668 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c libImaging/Matrix.c -o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Matrix.o
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c libImaging/Quant.c -o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Quant.o
     354553 [main] python3 1816 fork: child -1 - forked process 12020 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
     354762 [main] python3 14316 fork: child -1 - forked process 2324 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c libImaging/RawDecode.c -o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/RawDecode.o
    gcc -Wno-unused-result -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -ggdb -O2 -pipe -Wimplicit-function-declaration -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/build=/usr/src/debug/python3-3.4.3-1 -fdebug-prefix-map=/usr/src/ports/python3/python3-3.4.3-1.x86_64/src/Python-3.4.3=/usr/src/debug/python3-3.4.3-1 -DHAVE_LIBJPEG -DHAVE_LIBZ -I/usr/include/freetype2 -I/tmp/pip-build-g3f24mpy/Pillow/libImaging -I/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include -I/usr/include -I/usr/include/python3.4m -c libImaging/XbmEncode.c -o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/XbmEncode.o
     395591 [main] python3 1816 fork: child -1 - forked process 7316 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
     396080 [main] python3 14316 fork: child -1 - forked process 14028 died unexpectedly, retry 0, exit code 0xC0000005, errno 11
    gcc -shared -Wl,--enable-auto-image-base build/temp.cygwin-2.4.1-x86_64-3.4/_imaging.o build/temp.cygwin-2.4.1-x86_64-3.4/decode.o build/temp.cygwin-2.4.1-x86_64-3.4/encode.o build/temp.cygwin-2.4.1-x86_64-3.4/map.o build/temp.cygwin-2.4.1-x86_64-3.4/display.o build/temp.cygwin-2.4.1-x86_64-3.4/outline.o build/temp.cygwin-2.4.1-x86_64-3.4/path.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Access.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/AlphaComposite.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Resample.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Bands.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/BitDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Blend.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Chops.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Convert.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ConvertYCbCr.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Copy.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Crc32.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Crop.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Dib.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Draw.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Effects.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/EpsEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/File.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Fill.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Filter.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/FliDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Geometry.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/GetBBox.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/GifDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/GifEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/HexDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Histo.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/JpegDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/JpegEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/LzwDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Matrix.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ModeFilter.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/MspDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Negative.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Offset.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Pack.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PackDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Palette.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Paste.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Quant.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/QuantOctree.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/QuantHash.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/QuantHeap.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PcdDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PcxDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PcxEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Point.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/RankFilter.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/RawDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/RawEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Storage.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/SunRleDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/TgaRleDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Unpack.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/UnpackYCC.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/UnsharpMask.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/XbmDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/XbmEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ZipDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ZipEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/TiffDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Incremental.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Jpeg2KDecode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Jpeg2KEncode.o build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/BoxBlur.o -L/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/lib -L/usr/local/lib -L/usr/lib -L/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/lib/python3.4/config -L/usr/lib -ljpeg -lz -lpython3.4m -o build/lib.cygwin-2.4.1-x86_64-3.4/PIL/_imaging.cpython-34m.dll
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/_imaging.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/decode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/encode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/map.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/display.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/outline.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/path.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Access.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/AlphaComposite.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Resample.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Bands.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/BitDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Blend.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Chops.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Convert.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ConvertYCbCr.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Copy.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Crc32.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Crop.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Dib.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Draw.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Effects.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/EpsEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/File.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Fill.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Filter.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/FliDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Geometry.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/GetBBox.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/GifDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/GifEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/HexDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Histo.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/JpegDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/JpegEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/LzwDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Matrix.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ModeFilter.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/MspDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Negative.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Offset.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Pack.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PackDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Palette.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Paste.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Quant.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/QuantOctree.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/QuantHash.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/QuantHeap.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PcdDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PcxDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/PcxEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Point.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/RankFilter.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/RawDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/RawEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Storage.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/SunRleDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/TgaRleDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Unpack.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/UnpackYCC.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/UnsharpMask.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/XbmDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/XbmEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ZipDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/ZipEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/TiffDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Incremental.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Jpeg2KDecode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/Jpeg2KEncode.o: No such file or directory
    gcc: error: build/temp.cygwin-2.4.1-x86_64-3.4/libImaging/BoxBlur.o: No such file or directory
    error: command 'gcc' failed with exit status 1

    ----------------------------------------
Command "/cygdrive/c/Users/s7726/.virtualenvs/pillowtest/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-g3f24mpy/Pillow/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-20r5d54m-record/install-record.txt --single-version-externally-managed --compile --install-headers /cygdrive/c/Users/s7726/.virtualenvs/pillowtest/include/site/python3.4/Pillow" failed with error code 1 in /tmp/pip-build-g3f24mpy/Pillow

```

Try 

```
MAX_CONCURRENCY=1 pip install pillow
```

I'm wondering if the multithreaded compile is killing it, and the existing filters in `mp_compile:install()` aren't catching it because it's cygwin and not winpython. 

That appears to have done the trick. Thanks for your help. So it sounds like this is something that can be added to the filters you mentioned?

What's the value of `sys.platform` on cygwin?

`$ python`

``` python
import sys
print(sys.platform)
```

`cygwin`


Resolving patch:
diff --git a/mp_compile.py b/mp_compile.py
--- a/mp_compile.py
+++ b/mp_compile.py
@@ -56,13 +56,14 @@ def install():
 
     fl_pypy3 = hasattr(sys, 'pypy_version_info') and sys.version_info > (3, 0)
     fl_win = sys.platform.startswith('win')
+    fl_cygwin = sys.platform.startswith('cygwin')
 
     if fl_pypy3:
         # see https://github.com/travis-ci/travis-ci/issues/3587
         print("Single threaded build for pypy3")
         return
 
-    if fl_win:
+    if fl_win or fl_cygwin:
         #windows barfs on multiprocessing installs
         print("Single threaded build for windows")
         return


Test patch: