ci: use cross for musl x86_64 builds

This is necessary because jemalloc + musl + Ubuntu 16.04 is apparently
broken.

Moreover, jemalloc doesn't support i686, so we accept the performance
regression there.

See also: https://github.com/gnzlbg/jemallocator/issues/124

1 files changed, 4 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index d5c67a0b..bed33296 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -35,7 +35,10 @@ mod subject;
 // We don't unconditionally use jemalloc because it can be nice to use the
 // system's default allocator by default. Moreover, jemalloc seems to increase
 // compilation times by a bit.
-#[cfg(target_env = "musl")]
+//
+// Moreover, we only do this on 64-bit systems since jemalloc doesn't support
+// i686.
+#[cfg(all(target_env = "musl", target_pointer_width = "64"))]
 #[global_allocator]
 static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;