apple/pkl · error · PklException

Failed to write to $depsFile

Error message

Failed to write to $depsFile: ${e.message}

What it means

Thrown by CliProjectResolver.doRun when writing the generated PklProjectDependencies file (PklProjectDependencies.pem deps file next to the PklProject) fails with an IOException. `pkl project resolve` computes the dependency graph and persists it to disk; if the file cannot be opened or written, the resolver wraps the IOException in a PklException with this message, which includes the deps file path and the underlying IOException message.

Solutions

1. Check and fix write permissions on the project directory and any existing PklProjectDependencies file (e.g. chmod/chown)
2. Remove the stale deps file if it is owned by another user or immutable
3. Ensure the filesystem is writable (not mounted read-only) and has free disk space
4. Re-run `pkl project resolve`

try { resolveProject() } catch (PklException e) { if (e.getMessage().startsWith("Failed to write to")) handleUnwritableDepsFile(); else throw e; }

When it happens

Trigger: Running `pkl project resolve` when the target deps file cannot be written: read-only filesystem or directory, missing write permissions, the path is a directory instead of a file, or disk full.

Common situations: Running inside a read-only container or CI workspace; file owned by another user after running as root earlier; the project directory was made immutable; NFS/permissions issues in shared dev environments.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

• I/O error writing file `$outputFile`. Cause
• ioErrorLoadingModule
• ioErrorLoadingModule
• ioErrorReadingTestOutputFile
• ioErrorResolvingGlob

AI-assisted analysis of apple/pkl@f3efcbfc9b (2026-09-08). Data as JSON: /api/errors/b9ead56b29506cc1. Report an issue: GitHub.

Appendix: source

Thrown at pkl-cli/src/main/kotlin/org/pkl/cli/CliProjectResolver.kt:56

        PackageResolver.getInstance(
          SecurityManagers.standard(
            allowedModules,
            allowedResources,
            SecurityManagers.defaultTrustLevels,
            rootDir,
          ),
          httpClient,
          moduleCacheDir,
        )
      val dependencies = ProjectDependenciesResolver(project, packageResolver, errWriter).resolve()
      val depsFile =
        projectFile.parent.resolve(ProjectDependenciesManager.PKL_PROJECT_DEPS_FILENAME).toFile()
      try {
        depsFile.outputStream().use { dependencies.writeTo(it) }
        consoleWriter.appendLine(depsFile.toString())
        consoleWriter.flush()
      } catch (e: IOException) {
        throw PklException("Failed to write to $depsFile: ${e.message}", e)
      }
    }
  }
}

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