Commit ff0b7fe29a

@@ -6289,6 +6289,12 @@ LinkLib *add_link_lib(CodeGen *g, Buf *name) {
     if (is_libc && g->libc_link_lib != nullptr)
         return g->libc_link_lib;
 
+    if (g->enable_cache && is_libc && g->zig_target.os != OsMacOSX && g->zig_target.os != OsIOS) {
+        fprintf(stderr, "TODO linking against libc is currently incompatible with `--cache on`.\n"
+        "Zig is not yet capable of determining whether the libc installation has changed on subsequent builds.\n");
+        exit(1);
+    }
+
     for (size_t i = 0; i < g->link_libs_list.length; i += 1) {
         LinkLib *existing_lib = g->link_libs_list.at(i);
         if (buf_eql_buf(existing_lib->name, name)) {

@@ -17961,6 +17961,12 @@ static ZigType *ir_analyze_instruction_type_name(IrAnalyze *ira, IrInstructionTy
 }
 
 static ZigType *ir_analyze_instruction_c_import(IrAnalyze *ira, IrInstructionCImport *instruction) {
+    if (ira->codegen->enable_cache) {
+        ir_add_error(ira, &instruction->base,
+            buf_sprintf("TODO @cImport is incompatible with --cache on. The cache system currently is unable to detect subsequent changes in .h files."));
+        return ira->codegen->builtin_types.entry_invalid;
+    }
+
     AstNode *node = instruction->base.source_node;
     assert(node->type == NodeTypeFnCallExpr);
     AstNode *block_node = node->data.fn_call_expr.params.at(0);