sage.sh: export the ninja cache variable

Without this, the variable won't be set when sage reconfigures itself.
I've also learned that polymake does not support Samurai, preventing
me from fixing this properly within Sage itself.

diff --git a/sage.sh b/sage.sh
index 57db823f6a8cef5ba6c03ad30b281ad42deca862..7ebc70279b1d9d3168b05c23db740eb55cca4f95 100644 (file)
--- a/sage.sh
+++ b/sage.sh
@@ -15,6 +15,12 @@ _sage_find_ninja(){
   command -v "${NINJA}"
 }
 
+# We have to export this because sage likes to re-bootstrap and
+# re-configure itself every time you change a comment in an m4 file,
+# and it won't re-configure with this variable set. So then after
+# five minutes you'll get an error from --with-system-ninja=force.
+export ac_cv_path_NINJA=$(_sage_find_ninja)
+
 # Run ./configure within the SageMath git repository. This tweaks all
 # of the flags that I don't want to tweak manually:
 #
@@ -31,7 +37,6 @@ _sage_find_ninja(){
 # We also override the autoconf variable used to detect ninja, because
 # it does a version check that isn't compatible with samurai.
 sage-configure() {
-  ac_cv_path_NINJA=$(_sage_find_ninja) \
   ./configure \
     --enable-download-from-upstream-url \
     --enable-system-site-packages \