> The problem only occurs when installing several toolchains from PPA or tarball...
That's not my case. gcc-avr is not being installed from a PPA, it's being installed from the default Ubuntu 18.04 repositories.
> The problem only occurs when installing several toolchains from PPA or tarball...
That's not my case. gcc-avr is not being installed from a PPA, it's being installed from the default Ubuntu 18.04 repositories.