Blog / Standard Library

Happy late new year

January 7, 2026

I kinda fell off the planet for a while with family, holidays, and… writers’s block. But I’m back now, and prepared to take the time to come up with (hopefully) interesting things to write about again.

Today I’m going to talk about a new feature coming in Go 1.26, which relates to my series earlier in 2025 about contexts.

The new feature is mentioned very briefly in the release notes:

os/signal

NotifyContext now cancels the returned context with context.CancelCauseFunc and an error indicating which signal was received.

If you aren’t already quite familiar with the idea of context cancel causes, this new feature won’t make much sense. But not to worry! I explained those before!

But here’s the TL;DR;

  • You can create a context that can be canceled with a ‘cause’, which allows you to…
  • call the ‘Cause()’ method on the context, after its canceled, to get a more descriptive error message than the default ‘context canceled’ or ‘context deadline exceeded’.

And now, signal.NotifyContext will include a cause whenever the context is canceled due to a signal being received. This allows you to potentially treat SIGTERM and SIGINT differently in your graceful shutdowns, for example.

Woot!

Share this

Direct to your inbox, daily. I respect your privacy .

Unsure? Browse the archive .

Related Content

Aborting goroutines on error

I’m sorry for the delay in writing. Last week I was under the weather. Let’s pick up our discussion of goroutines and errors. Last time, I talked about errgroup, which makes it easy to run an arbitrary number of goroutines, and gather the first error (if any) that one returns. But what if that error renders the rest of the goroutines obsolete? A very common case is that any error means that the rest of the processing becomes moot.

Why is context.TODO not just a comment?

I’ve been on vacation for the last week, so haven’t written much. Let’s finally finish up the context package series with some reader feedback and questions! Joost Helberg wrote in with an interesting observation about context.TODO. In his own words: With regards to context.TODO, back in my early Go days, I thought the TODO was about the intent of this context. Like context.Background is for a background task and context.WithCancel for a job that can be canceled.

context.WithValue

func WithValue func WithValue(parent Context, key, val any) Context WithValue returns a derived context that points to the parent Context. In the derived context, the value associated with key is val. Use context Values only for request-scoped data that transits processes and APIs, not for passing optional parameters to functions. The provided key must be comparable and should not be of type string or any other built-in type to avoid collisions between packages using context.

Get daily content like this in your inbox!

Subscribe