Add assert that fallback targets must be available.

ehuss · ehuss · commit c8e6889e08fd · 2022-01-19T09:41:04.000-08:00
diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
@@ -536,7 +536,10 @@ impl Builder {
             }
             for (substr, fallback_target) in fallback {
                 if target_name.contains(substr) {
-                    return Target::from_compressed_tar(self, &tarball_name!(fallback_target));
+                    let t = Target::from_compressed_tar(self, &tarball_name!(fallback_target));
+                    // Fallbacks must always be available.
+                    assert!(t.available);
+                    return t;
                 }
             }
             Target::unavailable()

Original file line number	Diff line number	Diff line change
`@@ -536,7 +536,10 @@ impl Builder {`
`536`	`536`	`}`
`537`	`537`	`for (substr, fallback_target) in fallback {`
`538`	`538`	`if target_name.contains(substr) {`
`539`		`- return Target::from_compressed_tar(self, &tarball_name!(fallback_target));`
	`539`	`+ let t = Target::from_compressed_tar(self, &tarball_name!(fallback_target));`
	`540`	`+ // Fallbacks must always be available.`
	`541`	`+ assert!(t.available);`
	`542`	`+ return t;`
`540`	`543`	`}`
`541`	`544`	`}`
`542`	`545`	`Target::unavailable()`