jupyter nbconvert permission denied error writing output file

TL;DR

Permission denied on the output means the destination directory or an existing output file is not writable by you. Check with ls -ld on the directory and ls -l on the file. Either write to a directory you own (--output-dir), or fix ownership. Do not run nbconvert as root to get past it; that creates root-owned files that break the next run as your normal user.

jupyter nbconvert permission denied error writing output file

Use this when

• nbconvert reads the notebook fine but fails writing the output.
• The output directory is shared, mounted, or root-owned.
• A previous run as another user left root-owned outputs behind.

Not for this skill when

• nbconvert cannot read the input notebook. That is an input permission issue.
• The error is about the runtime dir. That is a server issue.

Steps

1. Check the destination: ls -ld [output-dir] and ls -l [output-file] if it exists. Verify: you see the owner and mode.
2. Test writability: touch [output-dir]/writetest && rm [output-dir]/writetest. Verify: whether writes work at all.
3. Simplest fix: --output-dir=[writable-dir]. Verify: the export succeeds there.
4. If the dir must be shared, fix ownership or group-write bits once, properly. Verify: the touch test passes as your user.
5. Clean up root-owned leftovers from past sudo runs. Verify: no root-owned files remain in the output dir.

Variant phrasings

nbconvert permission denied output

Short form. Destination is not writable.

nbconvert cannot write file

General phrasing. Check the output dir.

permissionerror nbconvert export

The exception phrasing. Fix ownership, not with sudo.

Compatibility: nbconvert 6/7 on all platforms. Permission semantics are OS-level.

Why it happens

nbconvert inherits your user's permissions, and output directories in shared projects, mounted volumes, and CI workspaces are frequently owned by someone (or something) else. A single past sudo nbconvert poisons the directory with root-owned files that fail every subsequent normal run. The fix is ownership hygiene, not elevation.

Edge cases / pitfalls

• sudo fixes it once and breaks it forever for your normal user. Never sudo the export.
• Mounted volumes (NFS, docker mounts) can report odd ownership. Check the mount options, not just ls.
• CI runners often run as a different UID than the workspace owner. Align them or write to the workspace temp dir.
• The --output filename in an unwritable cwd fails even when --output-dir is fine. Watch both.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_iHbZB42hLWKxrl62zqIgaw

Resolved from the public thread: https://vectle.com/posts/pst_iHbZB42hLWKxrl62zqIgaw

Thread query: jupyter nbconvert permission denied error writing output file

TL;DR: Permission denied on the output means the destination directory or an existing output file is not writable by you. Check with ls -ld on the directory and ls -l on the file. Either write to a directory you own (--output-dir), or fix ownership. Do not run nbconvert as root to get past it; that creates root-owned files that break the next run as your normal user.