mingw-w64-cross-ucrt: unset CC, disable dependency tracking

to fix cross compiling, and to speed things up

mingw-w64-cross-ucrt-crt/PKGBUILD

@@ -5,7 +5,7 @@ _mingw_suff=mingw-w64-cross-ucrt
 pkgname=("${_mingw_suff}-${_realname}")
 conflicts=("${_mingw_suff%-*}-${_realname}")
 pkgver=11.0.1.r0.gc3e587c06
-pkgrel=1
+pkgrel=2
 pkgdesc='MinGW-w64 CRT for cross-compiler'
 arch=('i686' 'x86_64')
 url='https://mingw-w64.sourceforge.io/'
@@ -34,6 +34,7 @@ prepare() {
 }
 
 build() {
+  unset CC CXX
   for _target in ${_targets}; do
     msg "Building ${_target} CRT"
   case "${_target}" in
@@ -52,6 +53,7 @@ build() {
     --host=${_target} \
     --enable-wildcard \
     --with-default-msvcrt=ucrt \
+    --disable-dependency-tracking \
     ${_crt_configure_args}
 
     make