I just built Ardour 6.3.0 from source. The interface is in English. I tried to look where to setup an other language but it seems that this is system dependent.
I run a Linux Mint 20 Ulyana 64-bit distribution with a LowLatency kernel. This system is setup with French language.
Il I install the “Free” version of Ardour, the interface is in French automatically.
So I don’t understand why the build version stays in English.
I thank you in advance for your answer.