c3-lang/libffi

diff --git a/.ci/build.sh b/.ci/build.sh
index a46e517..4f88ec7 100755
--- a/.ci/build.sh
+++ b/.ci/build.sh
@@ -2,6 +2,9 @@
 
 set -x
 
+# Special build tools are here...
+export PATH=~/i/bin:$PATH
+
 # This is a policy bound API key.  It can only be used with
 # https://github.com/libffi/rlgl-policy.git.
 RLGL_KEY=0LIBFFI-0LIBFFI-0LIBFFI-0LIBFFI
diff --git a/.ci/install.sh b/.ci/install.sh
index bfbfd97..9bdf97b 100755
--- a/.ci/install.sh
+++ b/.ci/install.sh
@@ -38,7 +38,8 @@ else
 
     set -x
     wget -qO - https://ftpmirror.gnu.org/autoconf/autoconf-2.71.tar.gz | tar -xvzf -
-    (cd autoconf-2.71; ./configure; make; make install)
+    mkdir -p ~/i
+    (cd autoconf-2.71; ./configure --prefix=~/i; make; make install)
 
     case $HOST in
 	mips64el-linux-gnu | sparc64-linux-gnu)