ariel@section9:/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/firebird/gen $ /usr/bin/ccache g++   -I/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/libatomic_ops/src   -DBOOT_BUILD -I../src/include/gen -I../src/include -I../src/vulcan -DNAMESPACE=Vulcan -DNDEBUG -ggdb -DFB_SEND_FLAGS=MSG_NOSIGNAL -DLINUX -DAMD64 -pipe -MMD -fPIC -fmessage-length=0 -O3 -fno-omit-frame-pointer  -pthread   -I/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/boost -L/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/boost/source/lib   -I/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/icu/source -I/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/icu/source/i18n -I/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/icu/source/common -L/mnt/windows/libreoffice-src/core/workdir/UnpackedTarball/icu/source/lib   -fno-rtti -fno-rtti -fno-rtti  -c ../src/jrd/gds.cpp -o ../temp/boot/jrd/gds.o
In file included from ../src/jrd/gds.cpp:59:0:
../src/jrd/../common/utils_proto.h:77:2: error: #error dont know how to compare strings case insensitive on this system
 #error dont know how to compare strings case insensitive on this system
  ^
../src/jrd/../common/utils_proto.h:94:2: error: #error dont know how to compare counted length strings case insensitive on this system
 #error dont know how to compare counted length strings case insensitive on this system
  ^
../src/jrd/gds.cpp: In function ‘void gds__trace_raw(const char*, unsigned int)’:
../src/jrd/gds.cpp:1078:27: warning: ignoring return value of ‘ssize_t write(int, const void*, size_t)’, declared with attribute warn_unused_result [-Wunused-result]
  write(file, text, length);
                           ^
How I copied the Git sources:
mkdir .ccache
export CCACHE_COMPRESS=1 CCACHE_DIR=./.ccache
ccache -M 5G
rsync -avx  /mnt/stuff/src/libreoffice/core/.git .
git pull
git reset --hard
./autogen.sh --with-parallelism=8 --without-krb5 --without-gssapi --without-java --without-help --disable-odk CFLAGS='-O3 -march=native -pipe' CXXFLAGS='-O3 -march=native -pipe'
export | grep CCACHE
time nice make