message: contrib: guix: More robust search paths, add checks
  store_path() previously only worked for cross compilation packages, we
  remove this assumption here
  Add CROSS_GCC_LIB variable which points to where gcc libs/headers are
  located
  Add gcc libs/headers to our CROSS_*_PATH environment variables
  Check that all directories in CROSS_*_PATH are sane
diff: @@ -30,23 +30,38 @@ fi
  # Given a package name and an output name, return the path of that output in our
  # current guix environment
  store_path() {
  - grep --extended-regexp "/[^-]{32}-${1}-cross-${HOST}-[^-]+${2:+-${2}}" "${GUIX_ENVIRONMENT}/manifest" \
  + grep --extended-regexp "/[^-]{32}-${1}-[^-]+${2:+-${2}}" "${GUIX_ENVIRONMENT}/manifest" \
  | head --lines=1 \
  | sed --expression='s|^[[:space:]]*"||' \
  --expression='s|"[[:space:]]*$||'
  }
  # Determine output paths to use in CROSS_* environment variables
  -CROSS_GLIBC="$(store_path glibc)"
  -CROSS_GLIBC_STATIC="$(store_path glibc static)"
  -CROSS_KERNEL="$(store_path linux-libre-headers)"
  -CROSS_GCC="$(store_path gcc)"
  +CROSS_GLIBC="$(store_path glibc-cross-${HOST})"
  +CROSS_GLIBC_STATIC="$(store_path glibc-cross-${HOST} static)"
  +CROSS_KERNEL="$(store_path linux-libre-headers-cross-${HOST})"
  +CROSS_GCC="$(store_path gcc-cross-${HOST})"
  +CROSS_GCC_LIBS=( "${CROSS_GCC}/lib/gcc/${HOST}"/* ) # This expands to an array of directories...
  +CROSS_GCC_LIB="${CROSS_GCC_LIBS[0]}" # ...we just want the first one (there should only be one)
  # Set environment variables to point Guix's cross-toolchain to the right
  # includes/libs for $HOST
  -export CROSS_C_INCLUDE_PATH="${CROSS_GCC}/include:${CROSS_GLIBC}/include:${CROSS_KERNEL}/include"
  -export CROSS_CPLUS_INCLUDE_PATH="${CROSS_GCC}/include/c++:${CROSS_GLIBC}/include:${CROSS_KERNEL}/include"
  -export CROSS_LIBRARY_PATH="${CROSS_GLIBC}/lib:${CROSS_GLIBC_STATIC}/lib:${CROSS_GCC}/lib:${CROSS_GCC}/${HOST}/lib:${CROSS_KERNEL}/lib"
  +#
  +# NOTE: CROSS_C_INCLUDE_PATH is missing ${CROSS_GCC_LIB}/include-fixed, because
  +# the limits.h in it is missing a '#include_next <limits.h>'
  +#
  +export CROSS_C_INCLUDE_PATH="${CROSS_GCC_LIB}/include:${CROSS_GLIBC}/include:${CROSS_KERNEL}/include"
  +export CROSS_CPLUS_INCLUDE_PATH="${CROSS_GCC}/include/c++:${CROSS_GCC}/include/c++/${HOST}:${CROSS_GCC}/include/c++/backward:${CROSS_C_INCLUDE_PATH}"
  +export CROSS_LIBRARY_PATH="${CROSS_GCC}/lib:${CROSS_GCC}/${HOST}/lib:${CROSS_GCC_LIB}:${CROSS_GLIBC}/lib:${CROSS_GLIBC_STATIC}/lib"
  +
  +# Sanity check CROSS_*_PATH directories
  +IFS=':' read -ra PATHS <<< "${CROSS_C_INCLUDE_PATH}:${CROSS_CPLUS_INCLUDE_PATH}:${CROSS_LIBRARY_PATH}"
  +for p in "${PATHS[@]}"; do
  + if [ ! -d "$p" ]; then
  + echo "'$p' doesn't exist or isn't a directory... Aborting..."
  + exit 1
  + fi
  +done
  # Disable Guix ld auto-rpath behavior
  export GUIX_LD_WRAPPER_DISABLE_RPATH=yes
  