chore(tests) add --- backtraces block

When set it will add `backtraces on;` to wasm context in nginx.conf

Author: casimiro

src/wasm/wrt/ngx_wrt_wasmer.c

@@ -74,6 +74,15 @@ ngx_wasmer_init_conf(ngx_wavm_conf_t *conf, ngx_log_t *log)
     char           *auto_compiler = NULL;
     wasm_config_t  *config;
 
+    ngx_wasm_assert(conf->backtraces != NGX_CONF_UNSET);
+
+    if (conf->backtraces) {
+        setenv("RUST_BACKTRACE", "FULL", 1);
+
+    } else {
+        setenv("RUST_BACKTRACE", "0", 1);
+    }
+
     config = wasm_config_new();
     if (config == NULL) {
         goto error;

src/wasm/wrt/ngx_wrt_wasmtime.c

@@ -135,9 +135,11 @@ ngx_wasmtime_init_conf(ngx_wavm_conf_t *conf, ngx_log_t *log)
 
     if (conf->backtraces) {
         setenv("WASMTIME_BACKTRACE_DETAILS", "1", 1);
+        setenv("RUST_BACKTRACE", "FULL", 1);
 
     } else {
         setenv("WASMTIME_BACKTRACE_DETAILS", "0", 1);
+        setenv("RUST_BACKTRACE", "0", 1);
     }
 
     config = wasm_config_new();

t/TestWasm.pm

@@ -104,14 +104,8 @@ add_block_preprocessor(sub {
         $block->set_value("request", "GET /t");
     }
 
-    # --- env variables
-
     my $main_config = $block->main_config || '';
 
-    $block->set_value("main_config",
-                      "env WASMTIME_BACKTRACE_DETAILS=1;\n"
-                      . $main_config);
-
     # --- load_nginx_modules: ngx_http_echo_module
 
     my @arr;
@@ -149,6 +143,7 @@ add_block_preprocessor(sub {
     # --- wasm_modules: on_phases
 
     my $wasm_modules = $block->wasm_modules;
+    my $backtraces = $block->backtraces;
     if (defined $wasm_modules) {
         @arr = split /\s+/, $wasm_modules;
         if (@arr) {
@@ -162,6 +157,11 @@ add_block_preprocessor(sub {
                                "    compiler " . $compiler . ";\n";
             }
 
+            if (defined $backtraces) {
+                $wasm_config = $wasm_config .
+                               "    backtraces on;\n";
+            }
+
             my $tls_skip_verify = $block->tls_skip_verify;
             my $tls_skip_host_check = $block->tls_skip_host_check;
             my $tls_trusted_certificate = $block->tls_trusted_certificate;