There’s a Nodejs utility, concurrently, which can be used to execute several commands at once, and it prefixes each one’s output with a tag. For example:

npx concurrently -n "frontend,backend" "launch_frontend.sh" "launch_backend.sh"

When used on Linux, stdout of the children point to a socket, whereas on Macos stdout remains file descriptor 1.

This means that the following command succeeds on Macos, but fails on Linux:
npx concurrently "echo 'hello world' > /dev/stdout"

However this command succeeds on both:
echo 'hello world' > /dev/stdout

Under concurrently on Linux /dev/stdout points to /proc/self/fd/1 which points to socket:[12345] rather than the usual /dev/pts/0 or similar.

So my problem is:
I have something I want to run, via npx concurrently, but that thing tries to open /dev/stdout. It works on Macos, but fails for users on Linux.

Given that I can’t easily modify the thing that is run, is there another way to around around this issue on Linux?

I have found one workaround, but it comes with some negatives. This is passing the --raw flag to concurrently. However as the name implies, it prevents the nice log processing that would otherwise occur.