Add issue for linux x32 failing to build

.travis.yml

@@ -94,6 +94,8 @@ matrix:
       osx_image: xcode8.3
       rust: nightly
     # not available on stable
+    # without --release the build fails
+    # see https://github.com/rust-lang/rust/issues/45417
     - env: TARGET=x86_64-unknown-linux-gnux32 OPT="--release"
       rust: nightly
 

ci/run.sh

@@ -69,6 +69,7 @@ if [ "$QEMU" != "" ]; then
 fi
 
 # FIXME: x86_64-unknown-linux-gnux32 fail to compile wihout --release
+# See https://github.com/rust-lang/rust/issues/45417
 opt=
 if [ "$TARGET" = "x86_64-unknown-linux-gnux32" ]; then
   opt="--release"