Improve error message for unresolved toolchains

bazelbuild · Mar 29, 2022 · 348c85d · 348c85d
1 parent 33de02a
commit 348c85d
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Showing 2 changed files with 8 additions and 16 deletions.
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ToolchainResolutionFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ToolchainResolutionFunction.java
@@ -570,20 +570,12 @@ protected Code getDetailedCode() {
     }
 
     private static String getMessage(List<Label> missingToolchainTypes) {
-      if (missingToolchainTypes.size() == 1
-          && Iterables.getOnlyElement(missingToolchainTypes)
-              .toString()
-              .equals("@bazel_tools//tools/cpp:toolchain_type")) {
-        return "No matching toolchains found for types @bazel_tools//tools/cpp:toolchain_type. "
-            + "Maybe --incompatible_use_cc_configure_from_rules_cc has been flipped and there "
-            + "is no default C++ toolchain added in the WORKSPACE file? See "
-            + "https://github.com/bazelbuild/bazel/issues/10134 for details and migration "
-            + "instructions.";
-      }
-
+      List<String> labelStrings =
+          missingToolchainTypes.stream().map(Label::toString).collect(Collectors.toList());
       return String.format(
-          "no matching toolchains found for types %s",
-          missingToolchainTypes.stream().map(Label::toString).collect(joining(", ")));
+          "No matching toolchains found for types %s. "
+          + "To debug, rerun with --toolchain_resolution_debug='%s'",
+          String.join(", ", labelStrings), String.join("|", labelStrings));
     }
   }
 

diff --git a/src/test/shell/integration/toolchain_test.sh b/src/test/shell/integration/toolchain_test.sh
@@ -436,7 +436,7 @@ use_toolchain(
 EOF
 
   bazel build "//${pkg}/demo:use" &> $TEST_log && fail "Build failure expected"
-  expect_log "While resolving toolchains for target //${pkg}/demo:use: no matching toolchains found for types //${pkg}/toolchain:test_toolchain"
+  expect_log "While resolving toolchains for target //${pkg}/demo:use: No matching toolchains found for types //${pkg}/toolchain:test_toolchain. To debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain'"
 }
 
 function test_multiple_toolchain_use_in_rule {
@@ -526,7 +526,7 @@ use_toolchains(
 EOF
 
   bazel build "//${pkg}/demo:use" &> $TEST_log && fail "Build failure expected"
-  expect_log "While resolving toolchains for target //${pkg}/demo:use: no matching toolchains found for types //${pkg}/toolchain:test_toolchain_2"
+  expect_log "While resolving toolchains for target //${pkg}/demo:use: No matching toolchains found for types //${pkg}/toolchain:test_toolchain_2. To debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain_2'"
 }
 
 function test_toolchain_use_in_rule_non_required_toolchain {
@@ -781,7 +781,7 @@ EOF
     --host_platform="//${pkg}:platform1" \
     --platforms="//${pkg}:platform1" \
     "//${pkg}/demo:use" &> $TEST_log && fail "Build failure expected"
-  expect_log "While resolving toolchains for target //${pkg}/demo:use: no matching toolchains found for types //${pkg}/toolchain:test_toolchain"
+  expect_log "While resolving toolchains for target //${pkg}/demo:use: No matching toolchains found for types //${pkg}/toolchain:test_toolchain. To debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain'"
   expect_not_log 'Using toolchain: rule message:'
 }