Define a SAGE_CONFIGURE_BOOST environment variable in the build shell

This makes the top-level configure --with-boost=... available for
package configurations. It is then passed down into brial's configure.

Author: vbraun

build/bin/sage-build-env

@@ -88,6 +88,13 @@ if [ "x$SAGE_BUILD_ENV_SOURCED" = "x" ]; then
         export SAGE_CONFIGURE_PARI="--with-pari=$SAGE_PARI_PREFIX"
     fi
 
+    # This is usually blank if the system boost is used
+    if [ -n "$SAGE_BOOST_PREFIX" ]; then
+        # Some packages that depend on boost accept a --with-boost=<prefix> flag to
+        # their ./configure scripts. Thus we deal with this just as with GMP above.
+        export SAGE_CONFIGURE_BOOST="--with-boost=$SAGE_BOOST_PREFIX"
+    fi
+
     # Optimization flags.
     #
     # The compiler flags are set in order of priority by

build/bin/sage-build-env-config.in

@@ -58,6 +58,8 @@ export SAGE_SUITESPARSE_PREFIX="@SAGE_SUITESPARSE_PREFIX@"
 
 export SAGE_CONFIGURE_FFLAS_FFPACK="@SAGE_CONFIGURE_FFLAS_FFPACK@"
 
+export SAGE_BOOST_PREFIX="@SAGE_BOOST_PREFIX@"
+
 export SAGE_HAVE_LIBJPEG="@SAGE_HAVE_LIBJPEG@"
 
 export SAGE_FRICAS_LISP="@SAGE_FRICAS_LISP@"

build/pkgs/brial/spkg-install.in

@@ -7,6 +7,7 @@ cd src
 cp "$SAGE_ROOT"/config/config.* .
 sdh_configure \
     --enable-shared --disable-static \
+    $SAGE_CONFIGURE_BOOST \
     --with-boost-unit-test-framework=no
 sdh_make
 sdh_make_install

m4/ax_boost_base.m4

@@ -79,6 +79,7 @@ AS_IF([test "x$want_boost" = "xyes"],
       [_AX_BOOST_BASE_RUNDETECT([$1],[$2],[$3])])
 AC_SUBST(BOOST_CPPFLAGS)
 AC_SUBST(BOOST_LDFLAGS)
+AC_SUBST(SAGE_BOOST_PREFIX,[$_AX_BOOST_BASE_boost_path])
 ])