1 files changed, 63 insertions, 17 deletions

diff --git a/Source/CTest/cmCTestMultiProcessHandler.cxx b/Source/CTest/cmCTestMultiProcessHandler.cxx
index 37679b9..2192843 100644
--- a/Source/CTest/cmCTestMultiProcessHandler.cxx
+++ b/Source/CTest/cmCTestMultiProcessHandler.cxx
@@ -196,8 +196,40 @@ bool cmCTestMultiProcessHandler::StartTestProcess(int test)
   // working directory because FinishTestProcess() will try to unlock them
   this->LockResources(test);
 
-  if (!this->TestsHaveSufficientResources[test]) {
-    testRun->StartFailure("Insufficient resources");
+  if (!this->ResourceAllocationErrors[test].empty()) {
+    std::ostringstream e;
+    e << "Insufficient resources for test " << this->Properties[test]->Name
+      << ":\n\n";
+    for (auto const& it : this->ResourceAllocationErrors[test]) {
+      switch (it.second) {
+        case ResourceAllocationError::NoResourceType:
+          e << "  Test requested resources of type '" << it.first
+            << "' which does not exist\n";
+          break;
+
+        case ResourceAllocationError::InsufficientResources:
+          e << "  Test requested resources of type '" << it.first
+            << "' in the following amounts:\n";
+          for (auto const& group : this->Properties[test]->ResourceGroups) {
+            for (auto const& requirement : group) {
+              if (requirement.ResourceType == it.first) {
+                e << "    " << requirement.SlotsNeeded
+                  << (requirement.SlotsNeeded == 1 ? " slot\n" : " slots\n");
+              }
+            }
+          }
+          e << "  but only the following units were available:\n";
+          for (auto const& res :
+               this->ResourceAllocator.GetResources().at(it.first)) {
+            e << "    '" << res.first << "': " << res.second.Total
+              << (res.second.Total == 1 ? " slot\n" : " slots\n");
+          }
+          break;
+      }
+      e << "\n";
+    }
+    e << "Resource spec file:\n\n  " << this->TestHandler->ResourceSpecFile;
+    testRun->StartFailure(e.str(), "Insufficient resources");
     this->FinishTestProcess(testRun, false);
     return false;
   }
@@ -205,8 +237,9 @@ bool cmCTestMultiProcessHandler::StartTestProcess(int test)
   cmWorkingDirectory workdir(this->Properties[test]->Directory);
   if (workdir.Failed()) {
     testRun->StartFailure("Failed to change working directory to " +
-                          this->Properties[test]->Directory + " : " +
-                          std::strerror(workdir.GetLastResult()));
+                            this->Properties[test]->Directory + " : " +
+                            std::strerror(workdir.GetLastResult()),
+                          "Failed to change working directory");
   } else {
     if (testRun->StartTest(this->Completed, this->Total)) {
       // Ownership of 'testRun' has moved to another structure.
@@ -249,7 +282,8 @@ bool cmCTestMultiProcessHandler::AllocateResources(int index)
 
 bool cmCTestMultiProcessHandler::TryAllocateResources(
   int index,
-  std::map<std::string, std::vector<cmCTestBinPackerAllocation>>& allocations)
+  std::map<std::string, std::vector<cmCTestBinPackerAllocation>>& allocations,
+  std::map<std::string, ResourceAllocationError>* errors)
 {
   allocations.clear();
 
@@ -264,18 +298,28 @@ bool cmCTestMultiProcessHandler::TryAllocateResources(
     ++processIndex;
   }
 
+  bool result = true;
   auto const& availableResources = this->ResourceAllocator.GetResources();
   for (auto& it : allocations) {
     if (!availableResources.count(it.first)) {
-      return false;
-    }
-    if (!cmAllocateCTestResourcesRoundRobin(availableResources.at(it.first),
-                                            it.second)) {
-      return false;
+      if (errors) {
+        (*errors)[it.first] = ResourceAllocationError::NoResourceType;
+        result = false;
+      } else {
+        return false;
+      }
+    } else if (!cmAllocateCTestResourcesRoundRobin(
+                 availableResources.at(it.first), it.second)) {
+      if (errors) {
+        (*errors)[it.first] = ResourceAllocationError::InsufficientResources;
+        result = false;
+      } else {
+        return false;
+      }
     }
   }
 
-  return true;
+  return result;
 }
 
 void cmCTestMultiProcessHandler::DeallocateResources(int index)
@@ -316,11 +360,13 @@ bool cmCTestMultiProcessHandler::AllResourcesAvailable()
 
 void cmCTestMultiProcessHandler::CheckResourcesAvailable()
 {
-  for (auto test : this->SortedTests) {
-    std::map<std::string, std::vector<cmCTestBinPackerAllocation>> allocations;
-    this->TestsHaveSufficientResources[test] =
-      !this->TestHandler->UseResourceSpec ||
-      this->TryAllocateResources(test, allocations);
+  if (this->TestHandler->UseResourceSpec) {
+    for (auto test : this->SortedTests) {
+      std::map<std::string, std::vector<cmCTestBinPackerAllocation>>
+        allocations;
+      this->TryAllocateResources(test, allocations,
+                                 &this->ResourceAllocationErrors[test]);
+    }
   }
 }
 
@@ -407,7 +453,7 @@ bool cmCTestMultiProcessHandler::StartTest(int test)
   }
 
   // Allocate resources
-  if (this->TestsHaveSufficientResources[test] &&
+  if (this->ResourceAllocationErrors[test].empty() &&
       !this->AllocateResources(test)) {
     this->DeallocateResources(test);
     return false;