Improve unresolved toolchains error

Add link to general platforms docs in response to feedback
bazelbuild · May 4, 2022 · e80defa · e80defa
1 parent 348c85d
commit e80defa
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Showing 2 changed files with 7 additions and 5 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
@@ -573,8 +573,10 @@ private static String getMessage(List<Label> missingToolchainTypes) {
       List<String> labelStrings =
           missingToolchainTypes.stream().map(Label::toString).collect(Collectors.toList());
       return String.format(
-          "No matching toolchains found for types %s. "
-          + "To debug, rerun with --toolchain_resolution_debug='%s'",
+          "No matching toolchains found for types %s."
+          + "\nTo debug, rerun with --toolchain_resolution_debug='%s'"
+          + "\nIf platforms or toolchains are a new concept to you, we'd encourage reading "
+          + "https://bazel.build/concepts/platforms-intro.",
           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 //${pkg}/toolchain:test_toolchain. To debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain'"
+  expect_log "While resolving toolchains for target //${pkg}/demo:use: No matching toolchains found for types //${pkg}/toolchain:test_toolchain.\nTo debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain\nIf platforms or toolchains are a new concept to you, we'd encourage reading https://bazel.build/concepts/platforms-intro.'"
 }
 
 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 //${pkg}/toolchain:test_toolchain_2. To debug, rerun with --toolchain_resolution_debug='//${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.\nTo debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain_2\nIf platforms or toolchains are a new concept to you, we'd encourage reading https://bazel.build/concepts/platforms-intro.'"
 }
 
 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 //${pkg}/toolchain:test_toolchain. To debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain'"
+  expect_log "While resolving toolchains for target //${pkg}/demo:use: No matching toolchains found for types //${pkg}/toolchain:test_toolchain.\nTo debug, rerun with --toolchain_resolution_debug='//${pkg}/toolchain:test_toolchain\nIf platforms or toolchains are a new concept to you, we'd encourage reading https://bazel.build/concepts/platforms-intro.'"
   expect_not_log 'Using toolchain: rule message:'
 }