New version of CYGWIN includes ccache 3.1.9-2, breaks the windows build.

When using the old default version of CYGWIN ccache (2.4-1), ccache would be found but disabled:

    Build performance summary:
    * Cores to use: 4
    * Memory limit: 7871 MB
    * ccache status: installed, but disabled (version older than 3.1.4)

Under the new version (3.1.9-2), ccache would be found and enabled:

    Build performance summary:
    * Cores to use: 4
    * Memory limit: 7871 MB
    * ccache status: installed and in use

When the new ccache build is present, you get CC/CXX invocations like this ("\" added for readability):

    /cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/fixpath.exe \
    -c \
    CCACHE_COMPRESS=1 CCACHE_SLOPPINESS=time_macros \
    /usr/bin/ccache /cygdrive/c/progra~2/micros~2.0/vc/bin/amd64/cl \
    -nologo -Zi -MD -Zc:wchar_t- -W3 -wd4800 \
    ...deleted...

Notice that -c is a fixpath.exe option, but then fixpath tries to run the string:

    CCACHE_COMPRESS=1 ...deleted...

as a command, which obviously fails. I'm assuming this is supposed to be a shell option, but under fixpath, it fails.

(/cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/fixpath.exe -c CCACHE_COMPRESS=1 CCACHE_SLOPPINESS=time_macros /usr/bin/ccache /cygdrive/c/progra~2/micros~2.0/vc/bin/amd64/cl -nologo -Zi -MD -Zc:wchar_t- -W3 -wd4800 -D_STATIC_CPPLIB -D_DISABLE_DEPRECATE_STATIC_CPPLIB -DWIN32_LEAN_AND_MEAN -D_CRT_S
ECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE -DWIN32 -DIAL -D_AMD64_ -Damd64 -D_LITTLE_ENDIAN -DWINDOWS -DDEBUG -DARCH='"amd64"' -Damd64 -DRELEASE='""' -I/cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/include -I/cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/include/windows -I/cygdrive/d/java/ws/tl/jdk/src/share/javavm/export -I/cygdrive/d/java/ws/tl/jdk/src/windows/javavm/export -I/cygdrive/d/java/ws/tl/jdk/src/share/native/common -I/cygdrive/d/java/ws/tl/jdk/src/windows/native/common -I/cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/gensrc_headers -I/cygdrive/d/java/ws/tl/jdk/src/share/native/java/lang/fdlibm/include -DLOGGING -Od
  -DTHIS_FILE='"e_acos.c"' -c -showIncludes -Fd/cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/objs/libfdlibm/e_acos.pdb -Fm/cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/objs/libfdlibm/e_acos.map -Fo/cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/objs/libfdlibm/e_acos.obj /cygdrive/d/java/ws/tl/jdk/src/share/native/java/lang/fdlibm/src/e_acos.c ; echo $? > /cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/objs/libfdlibm/e_acos.d.exitvalue) | /usr/bin/tee /cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/objs/libfdlibm/e_acos.d.raw | /usr/bin/grep -v "^Note: including file:" && exit `cat /cygdrive/d/java/ws/tl/build/windows-x86_64-normal-server-fastdebug/jdk/objs/libfdlibm/e_acos.d.exitvalue`

Could not start process! Failed with error 2: The system cannot find the file specified.