Commit 96a5f7c8ed

@@ -8657,6 +8657,12 @@ fn zirEnumFromInt(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError
         return Air.internedToRef((try mod.getCoerced(int_val, dest_ty)).toIntern());
     }
 
+    if (dest_ty.intTagType(mod).zigTypeTag(mod) == .ComptimeInt) {
+        return sema.failWithNeededComptime(block, operand_src, .{
+            .needed_comptime_reason = "value being casted to enum with 'comptime_int' tag type must be comptime-known",
+        });
+    }
+
     if (try sema.typeHasOnePossibleValue(dest_ty)) |opv| {
         const result = Air.internedToRef(opv.toIntern());
         // The operand is runtime-known but the result is comptime-known. In

@@ -0,0 +1,14 @@
+export fn entry() void {
+    const Tag = enum(comptime_int) { a, b };
+
+    var v: u32 = 0;
+    _ = &v;
+    _ = @as(Tag, @enumFromInt(v));
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :6:31: error: unable to resolve comptime value
+// :6:31: note: value being casted to enum with 'comptime_int' tag type must be comptime-known