Second attempt at workaround for docs.rs compiler

serde/build.rs

@@ -53,6 +53,11 @@ fn rustc_minor_version() -> Option<u32> {
         Err(_) => return None,
     };
 
+    // Temporary workaround to support the old 1.26-dev compiler on docs.rs.
+    if version.contains("0eb87c9bf") {
+        return Some(25);
+    }
+
     let mut pieces = version.split('.');
     if pieces.next() != Some("rustc 1") {
         return None;