[Bug] Emoji triggers PDF-export crash and restarts container (CodiMD 2.6.0) · Issue #1932 · hackmdio/codimd · GitHub

Describe the bug

Exporting a note to PDF in CodiMD 2.6.0 crashes PhantomJS whenever the note contains certain emoji characters, which restarts the whole container.

To Reproduce

Create or edit a note.
Insert any emoji (e.g. 😀).
Click Export → PDF.
The request hangs and the container restarts.

Expected behavior

A PDF should be generated successfully.
The service should remain online.

Actual behavior

PDF generation fails.
docker logs show PhantomJS crashing with SIGFPE.
The CodiMD container restarts automatically.

Environment

Item	Value
CodiMD ver.	2.6.0
Deployment	docker-compose
Node ver.	16.20.2 (image default)
Base OS	Debian Buster
PDF engine	markdown-pdf + PhantomJS

docker-compose excerpt (masked)

click to expand

services:
  codimd:
    image: <PRIVATE_REGISTRY>/hackmdio/hackmd:2.6.0
    environment:
      CMD_URL_PATH: codimd
      CMD_DOMAIN: <YOUR_DOMAIN>
      CMD_PROTOCOL_USESSL: "true"
      QT_QPA_PLATFORM: ""
      # Database
      CMD_DB_URL: postgres://codimd:<MASKED_PW>@codimd_db/codimd
      # Misc
      CMD_EMAIL: "false"
      CMD_PLANTUML_SERVER: https://<YOUR_DOMAIN>/plantuml
      CMD_ALLOW_ANONYMOUS: "false"
      CMD_ALLOW_ANONYMOUS_EDITS: "false"
      CMD_CSP_ENABLE: "false"

Logs (full excerpt)

2025-07-09T06:13:04.445Z info:  <MASKED_IP> - - [09/Jul/2025:06:13:04 +0000] "GET /me HTTP/1.1" 304 - "https://<YOUR_DOMAIN>/codimd/ixLMZtInSNiOnrbOkQ-Q_w" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36 Edg/138.0.0.0"
2025-07-09T06:13:06.517Z info:  <MASKED_IP> - - [09/Jul/2025:06:13:06 +0000] "GET /uploads/upload_845dbee74d2337302b91fb126a4691db.png HTTP/1.1" 200 32405 "https://<YOUR_DOMAIN>/codimd/ixLMZtInSNiOnrbOkQ-Q_w" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36 Edg/138.0.0.0"
2025-07-09T06:13:20.968Z info:  deserializeUser: c35f23dd-2732-46b7-9283-15b14eac234b
2025-07-09T06:13:21.478Z error: uncaughtException: Command failed: /home/hackmd/app/node_modules/phantomjs-prebuilt/lib/phantom/bin/phantomjs /home/hackmd/app/node_modules/markdown-pdf/phantom/render.js /tmp/tmp-<MASKED>.html /tmp/tmp-<MASKED>.pdf /home/hackmd/app /home/hackmd/app/node_modules/markdown-pdf/runnings.js /home/hackmd/app/node_modules/markdown-pdf/css/pdf.css /home/hackmd/app/node_modules/highlight.js/styles/github-gist.css A4 portrait 2cm 0 10000
PhantomJS has crashed. Please read the bug reporting guide at
<http://phantomjs.org/bug-reporting.html> and file a bug report.
Error: Command failed: /home/hackmd/app/node_modules/phantomjs-prebuilt/lib/phantom/bin/phantomjs /home/hackmd/app/node_modules/markdown-pdf/phantom/render.js /tmp/tmp-<MASKED>.html /tmp/tmp-<MASKED>.pdf /home/hackmd/app /home/hackmd/app/node_modules/markdown-pdf/runnings.js /home/hackmd/app/node_modules/markdown-pdf/css/pdf.css /home/hackmd/app/node_modules/highlight.js/styles/github-gist.css A4 portrait 2cm 0 10000
PhantomJS has crashed. Please read the bug reporting guide at
<http://phantomjs.org/bug-reporting.html> and file a bug report.
    at ChildProcess.exithandler (node:child_process:402:12)
    at ChildProcess.emit (node:events:513:28)
    at maybeClose (node:internal/child_process:1100:16)
    at Socket.<anonymous> (node:internal/child_process:458:11)
    at Socket.emit (node:events:513:28)
    at Pipe.<anonymous> (node:net:301:12)
2025-07-09T06:13:21.481Z error:  Process will exit now.
Info: try to connect to tcp://codimd_db in port 5432
2025/07/09 06:13:22 portchecker.go:56: dial tcp codimd_db:5432: connect: connection success

Possible cause / context

Matches Rendering Emojis hajareshyam/pdf-creator-node#45 — PhantomJS cannot render certain emoji/Unicode glyphs.
Removing all emoji lets the export succeed → strong evidence of an encoding issue.
PhantomJS is unmaintained; CodiMD relies on it via markdown-pdf.

Potential solutions

Upgrade to CodiMD 3.x (if it has moved to a Chromium/Puppeteer backend).
Replace PhantomJS with Puppeteer/Playwright in a custom build.
Test latest phantomjs-prebuilt patch to confirm whether the crash persists.

Help wanted

Can maintainers reproduce this crash with an emoji-containing note?
Is there an official plan to migrate away from PhantomJS?
Any patch or workaround would be greatly appreciated.

[Bug] Emoji triggers PDF-export crash and restarts container (CodiMD 2.6.0) · Issue #1932 · hackmdio/codimd · GitHub

Uh oh!

[Bug] Emoji triggers PDF-export crash and restarts container (CodiMD 2.6.0) #1932

Describe the bug

To Reproduce

Expected behavior

Actual behavior

Environment

docker-compose excerpt (masked)

Logs (full excerpt)

Possible cause / context

Potential solutions

Help wanted

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

[Bug] Emoji triggers PDF-export crash and restarts container (CodiMD 2.6.0) · Issue #1932 · hackmdio/codimd · GitHub

Uh oh!

[Bug] Emoji triggers PDF-export crash and restarts container (CodiMD 2.6.0) #1932

Description

Describe the bug

To Reproduce

Expected behavior

Actual behavior

Environment

docker-compose excerpt (masked)

Logs (full excerpt)

Possible cause / context

Potential solutions

Help wanted

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions