I’ve recently moved one of my projects from yarn v1 to v2. Everything has gone well but the new version of yarn seems to be very verbose in its log output.

Namely, lots of these informational level logs explaining what’s happening with each dependency:

$ yarn install
➤ YN0000: ┌ Resolution step
➤ YN0002: │ @buffetjs/core@npm:3.3.3-next.2 [29e54] doesn't provide @babel/runtime (peb6c0), requested by react-dates
➤ YN0002: │ @buffetjs/core@npm:3.3.3-next.2 [2c39f] doesn't provide @babel/runtime (p5ef06), requested by react-dates
➤ YN0002: │ @buffetjs/core@npm:3.3.3-next.2 [526e4] doesn't provide @babel/runtime (p70a11), requested by react-dates
➤ YN0002: │ @buffetjs/core@npm:3.3.3-next.2 [77946] doesn't provide @babel/runtime (p82dce), requested by react-dates
➤ YN0002: │ @buffetjs/core@npm:3.3.3-next.2 [b3fd8] doesn't provide @babel/runtime (pf9b95), requested by react-dates
➤ YN0002: │ @buffetjs/core@npm:3.3.3-next.2 [df35a] doesn't provide @babel/runtime (p01176), requested by react-dates
➤ YN0002: │ @buffetjs/custom@npm:3.3.3-next.2 [29e54] doesn't provide react-dom (pb4e73), requested by @buffetjs/core
➤ YN0002: │ @buffetjs/custom@npm:3.3.3-next.2 [77946] doesn't provide react-dom (p49d12), requested by @buffetjs/core
➤ YN0002: │ @buffetjs/custom@npm:3.3.3-next.2 [b3fd8] doesn't provide react-dom (pe5a5d), requested by @buffetjs/core
➤ YN0002: │ @buffetjs/styles@npm:3.3.3-next.2 [29e54] doesn't provide @babel/runtime (p89727), requested by react-dates
➤ YN0002: │ @buffetjs/styles@npm:3.3.3-next.2 [29e54] doesn't provide moment (pbdbf3), requested by react-dates
➤ YN0002: │ @buffetjs/styles@npm:3.3.3-next.2 [29e54] doesn't provide react-dom (pedb8f), requested by react-dates
➤ YN0002: │ @buffetjs/styles@npm:3.3.3-next.2 [29e54] doesn't provide react-dom (p4a416), requested by react-tooltip
...snip...

I’m sure it’s useful but I don’t want to see it all the time, especially during a Docker build.

I did the usual searches: “yarn 2 log verbosity”, “yarn 2 lots of output”, etc to see if anyone else was asking how to reduce the verbosity but nothing turned up. Apparently I’m alone.

So for anyone who lands on this page, I hope this helps.

The solution

Yarn config has a logFilters key that we can use to control log outputs.

In my case, I don’t want to see those YN0002 log lines. They can be filtered out by adding the following lines to your .yarnrc.yml:

logFilters:
  - code: "YN0002"
    level: "discard"

All sorted.