Don't error out when h2spec can't be compiled

Makefile

@@ -71,8 +71,8 @@ test-build:: $(H2SPEC)
 
 $(H2SPEC):
 	$(gen_verbose) mkdir -p $(GOPATH)/src/github.com/summerwind
-	$(verbose) git clone --depth 1 https://github.com/summerwind/h2spec $(dir $(H2SPEC))
-	$(verbose) $(MAKE) -C $(dir $(H2SPEC)) build MAKEFLAGS=
+	$(verbose) git clone --depth 1 https://github.com/summerwind/h2spec $(dir $(H2SPEC)) || true
+	$(verbose) $(MAKE) -C $(dir $(H2SPEC)) build MAKEFLAGS= || true
 
 # Use erl_make_certs from the tested release during CI
 # and ensure that ct_helper is always recompiled.

test/h2spec_SUITE.erl

@@ -28,11 +28,16 @@ init_per_suite(Config) ->
 	case os:getenv("H2SPEC") of
 		false ->
 			skip;
-		_ ->
-			cowboy_test:init_http(h2spec, #{
-				env => #{dispatch => init_dispatch()},
-				max_concurrent_streams => 100
-			}, Config)
+		H2spec ->
+			case filelib:is_file(H2spec) of
+				false ->
+					skip;
+				true ->
+					cowboy_test:init_http(h2spec, #{
+						env => #{dispatch => init_dispatch()},
+						max_concurrent_streams => 100
+					}, Config)
+			end
 	end.
 
 end_per_suite(_Config) ->