Error: Chromium revision is not downloaded. Run "npm install" or "yarn install"

Question

I am trying to run the following command but I am getting the error like

pa11y http://example.com/ # Trying to run this on my terminal


Welcome to Pa11y
------------------------
Error: Chromium revision is not downloaded. Run "npm install" or "yarn install"
    at Launcher.launch (/usr/lib/node_modules/pa11y/node_modules/puppeteer/lib/Launcher.js:119:15)
    at async runPa11yTest (/usr/lib/node_modules/pa11y/lib/pa11y.js:106:29)
    at async pa11y (/usr/lib/node_modules/pa11y/lib/pa11y.js:55:19)
    at async runProgram (/usr/lib/node_modules/pa11y/bin/pa11y.js:122:19)

I spent around 3-4 hours to fix this but no luck. I have tried every possible solution on the internet which is posted by others who had faced similar errors.

Any help in this regard is helpful

Answer 1

Two questions:

1. Do you have Chromium installed? pa11y doesn't think so! It could be a wrong version installed if so, or installed in a way that pa11y can't find.
2. What OS are you running?

The answer to your question depends on your Operating System, because the version of Chromium you need is specific to your OS! If you're running Linux Alpine, the command would be something like this:

apk add -U --no-cache --allow-untrusted udev ttf-freefont chromium git

I had this problem when trying to run the Node package puppeteer (which uses Chromium) in a Docker container running node 12 alpine. I spent all weekend (yes...) to come to the 1 line (yes...) I needed. It turned out I needed to add the above line to my Dockerfile, which installs the necessary fonts and libraries and installs Chromium.

I also had to tell Puppeteer to skip installing Chromium, but I don't think that's applicable to your situation.

If you're running something other than Linux, check out these instructions for installing Chromium: https://www.chromium.org/getting-involved/download-chromium