Code Yarns ‍👨‍💻
Tech BlogPersonal Blog

Github.dev not working with uMatrix

📅 2021-Oct-29 ⬩ ✍️ Ashwin Nanjappa ⬩ 🏷️ github, umatrix ⬩ 📚 Archive

Problem

Github.dev allows me to open any Github repo of mine in a VSCode IDE in my browser itself. For browsing I use the Firefox browser with the uMatrix extension. When I opened my Github repo using github.dev, I noticed that several features, like the file Explorer on the left, were not working.

Solution

As my first step in the investigation, I disabled the uMatrix extension - the github.dev website was fully functional! So it was definitely uMatrix that was interfering with the operation of this website.

I decided to disable the matrix for the entire github.dev website, since I do not really mind doing that for this URL:

matrix-off: github.dev true

The file Explorer still did not load after this.

I decided to check the browser Console, by pressing F12. Here I saw that several external URLs that this website was trying to pull were being blocked and were highlighted in red. I noted down the base domain names of these URLs and disabled the matrix for all of them:

matrix-off: azureedge.net true
matrix-off: vscode-unpkg.net true
matrix-off: vscode-webview.net true

After doing this and refreshing the webpage, github.dev was fully functional!

Tried with: uMatrix 1.4.4 and Firefox 92.0.1