Fission-AI/OpenSpec · error · Error

Schema '${destinationName}' at ${destinationDir} changed on

Error message

Schema '${destinationName}' at ${destinationDir} changed on disk while the fork was being prepared. Aborted to preserve those concurrent changes; nothing was overwritten. Re-run the fork to overwrite the current contents.

What it means

Error "Schema '${destinationName}' at ${destinationDir} changed on disk while the fork was being prepared. Aborted to preserve those concurrent changes; nothing was overwritten. Re-run the fork to overwrite the current contents." thrown in Fission-AI/OpenSpec.

Source

Thrown at src/commands/schema.ts:831

          // Swap the staged fork into place. When a destination already exists,
          // move it aside to a sibling backup FIRST, then install the staged
          // fork; only once the install succeeds is the backup discarded. If the
          // install rename itself fails (e.g. a Windows lock), the backup is
          // moved back so the user's original destination is never lost.
          if (destinationExists) {
            if (spinner) spinner.text = `Replacing existing schema '${destinationName}'...`;

            // Revalidate immediately before the destructive move: if the
            // destination changed on disk while we were staging (or was removed),
            // its fingerprint no longer matches what the user authorized. Abort
            // WITHOUT touching it, so the concurrent changes are preserved. The
            // outer catch cleans up staging.
            const currentFingerprint = fs.existsSync(destinationDir)
              ? fingerprintDir(destinationDir)
              : null;
            if (currentFingerprint !== authorizedDestinationFingerprint) {
              throw new Error(
                `Schema '${destinationName}' at ${destinationDir} changed on disk while the fork was being prepared. ` +
                  `Aborted to preserve those concurrent changes; nothing was overwritten. Re-run the fork to overwrite the current contents.`
              );
            }

            const backupDir = `${destinationDir}.fork-backup-${process.pid}-${Date.now()}`;
            fs.renameSync(destinationDir, backupDir);
            try {
              fs.renameSync(stagingDir, destinationDir);
            } catch (installError) {
              // Install failed after the original was moved aside. Try to move
              // it back. If that restore ALSO fails, the original is stranded in
              // the backup dir — surface an error naming both the backup and the
              // destination so the user can recover manually, and attach the
              // original install error as the cause. Never swallow this.
              try {
                fs.renameSync(backupDir, destinationDir);
              } catch (restoreError) {

View on GitHub (pinned to 6926ccb18a)

When it happens

Trigger: Thrown at src/commands/schema.ts:831 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Fission-AI/OpenSpec@6926ccb18a (2026-08-25). Data as JSON: /api/errors/25a54721df83b7e6. Report an issue: GitHub.