Handle non-existence

Author: fmeum

src/main/java/com/google/devtools/build/lib/bazel/BazelRepositoryModule.java

@@ -122,6 +122,7 @@
 import com.google.devtools.build.lib.vfs.RootedPath;
 import com.google.devtools.common.options.OptionsBase;
 import com.google.devtools.common.options.OptionsParsingResult;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
 import java.time.Instant;
@@ -377,28 +378,40 @@ public void beforeCommand(CommandEnvironment env) throws AbruptExitException {
       }
       Path repoContentsCachePath = repositoryCache.getRepoContentsCache().getPath();
       if (repoContentsCachePath != null) {
+        Path resolvedOutputBase;
         try {
-          Path resolvedRepoContentsCache = repoContentsCachePath.resolveSymbolicLinks();
-          Path resolvedOutputBase = env.getOutputBase().resolveSymbolicLinks();
-          if (resolvedOutputBase.startsWith(resolvedOutputBase)) {
-            // This is dangerous as the repo contents cache GC may delete files in the output base.
-            throw new AbruptExitException(
-                detailedExitCode(
-                    """
-                  The output base [%s] is inside the repo contents cache [%s]. This can cause \
-                  spurious failures. Disable the repo contents cache with `--repo_contents_cache=`, \
-                  or specify `--repo_contents_cache=<path that doesn't contain the output base>`.
-                  """
-                        .formatted(resolvedOutputBase, resolvedRepoContentsCache),
-                    Code.BAD_REPO_CONTENTS_CACHE));
-          }
+          resolvedOutputBase = env.getOutputBase().resolveSymbolicLinks();
+        } catch (IOException e) {
+          throw new AbruptExitException(
+              detailedExitCode(
+                  "could not resolve output base: %s".formatted(e.getMessage()),
+                  Code.BAD_REPO_CONTENTS_CACHE),
+              e);
+        }
+        Path resolvedRepoContentsCache = repoContentsCachePath;
+        try {
+          resolvedRepoContentsCache = resolvedRepoContentsCache.resolveSymbolicLinks();
+        } catch (FileNotFoundException e) {
+          // Will be created later.
         } catch (IOException e) {
           throw new AbruptExitException(
               detailedExitCode(
                   "could not resolve repo contents cache path: %s".formatted(e.getMessage()),
                   Code.BAD_REPO_CONTENTS_CACHE),
               e);
         }
+        if (resolvedOutputBase.startsWith(resolvedOutputBase)) {
+          // This is dangerous as the repo contents cache GC may delete files in the output base.
+          throw new AbruptExitException(
+              detailedExitCode(
+                  """
+                  The output base [%s] is inside the repo contents cache [%s]. This can cause \
+                  spurious failures. Disable the repo contents cache with `--repo_contents_cache=`, \
+                  or specify `--repo_contents_cache=<path that doesn't contain the output base>`.
+                  """
+                      .formatted(resolvedOutputBase, resolvedRepoContentsCache),
+                  Code.BAD_REPO_CONTENTS_CACHE));
+        }
       }
       if (repoContentsCachePath != null
           && env.getWorkspace() != null

src/main/java/com/google/devtools/build/lib/remote/RemoteModule.java

@@ -111,6 +111,7 @@
 import io.netty.handler.codec.DecoderException;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.reactivex.rxjava3.plugins.RxJavaPlugins;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -344,22 +345,31 @@ public void beforeCommand(CommandEnvironment env) throws AbruptExitException {
     boolean enableRemoteDownloader = shouldEnableRemoteDownloader(remoteOptions);
 
     if (enableDiskCache) {
+      Path resolvedOutputBase;
       try {
-        Path resolvedOutputBase = env.getOutputBase().resolveSymbolicLinks();
-        Path resolvedDiskCache =
-            env.getWorkingDirectory().getRelative(remoteOptions.diskCache).resolveSymbolicLinks();
-        if (resolvedOutputBase.startsWith(resolvedDiskCache)) {
-          // This is dangerous as the disk cache GC may delete files in the output base.
-          throw createOptionsExitException(
-              "The output base [%s] cannot be a subdirectory of the --disk_cache directory [%s]"
-                  .formatted(resolvedOutputBase, resolvedDiskCache),
-              FailureDetails.RemoteOptions.Code.EXECUTION_WITH_INVALID_CACHE);
-        }
+        resolvedOutputBase = env.getOutputBase().resolveSymbolicLinks();
+      } catch (IOException e) {
+        throw createOptionsExitException(
+            "Failed to resolve output base: %s".formatted(e.getMessage()),
+            FailureDetails.RemoteOptions.Code.EXECUTION_WITH_INVALID_CACHE);
+      }
+      Path resolvedDiskCache = env.getWorkingDirectory().getRelative(remoteOptions.diskCache);
+      try {
+        resolvedDiskCache = resolvedDiskCache.resolveSymbolicLinks();
+      } catch (FileNotFoundException ignored) {
+        // Will be created later.
       } catch (IOException e) {
         throw createOptionsExitException(
             "Failed to resolve disk cache directory: %s".formatted(e.getMessage()),
             FailureDetails.RemoteOptions.Code.EXECUTION_WITH_INVALID_CACHE);
       }
+      if (resolvedOutputBase.startsWith(resolvedDiskCache)) {
+        // This is dangerous as the disk cache GC may delete files in the output base.
+        throw createOptionsExitException(
+            "The output base [%s] cannot be a subdirectory of the --disk_cache directory [%s]"
+                .formatted(resolvedOutputBase, resolvedDiskCache),
+            FailureDetails.RemoteOptions.Code.EXECUTION_WITH_INVALID_CACHE);
+      }
       var gcIdleTask =
           DiskCacheGarbageCollectorIdleTask.create(remoteOptions, env.getWorkingDirectory());
       if (gcIdleTask != null) {