Determining correct GNU ARM toolchain to use with different versions of mbed-os

Is there a good resource for this?

It’s better to follow the ARM toolchain updated:

Current version is GCC 9.2.

And here is the related PR on Github:

Thanks but I do not understand your response, @ladislas . Production versions of software are not always ready to be updated to the latest versions of Mbed OS. Further, my understanding is that the same GCC toolchain used do develop a particular version of mbed OS should be used when developing projects that use that specific mbed OS. So, how do I synch the toolchain with Mbed OS?

For example, I have a project that uses mbed-os-5.11.1. How do I know which version of GCC toolchain to use when doing builds?

When you compile the code, mbed-cli will tell you which version it is expecting if you are out of range. I’m guessing gcc 6.x.x. If you are using the latest version of mbed, you can go with 9.x.x

Thanks, @ladislas, but I was hoping to find some sort of resource on Github,, or something of the like that would provide that information prior to building. ARM has the information somewhere and making it available to users would be a big help for those users building with different versions of Mbed OS.

A quick search on the google gets you this:

Further search and they actually do in the official documentation:

You can select the version you want. For example 5.11 will give you gcc 6 instead of 9 in 5.15.

Thanks, @ladislas. That is what I was looking for.