$ strace -e trace=file ardour3 2>&1 | grep '\.rc'
ardour: [INFO]: Loading ui configuration file /usr/local/etc/ardour3/ardour3_ui_dark.rc
access("/usr/local/etc/ardour3/ardour3_ui_dark.rc", R_OK) = 0
lstat64("/usr/local/etc/ardour3/ardour3_ui_dark.rc", {st_mode=S_IFREG|0644, st_size=65628, ...}) = 0
open("/usr/local/etc/ardour3/ardour3_ui_dark.rc", O_RDONLY|O_LARGEFILE) = 10
lstat64("/usr/local/etc/ardour3/ardour3_ui_dark.rc", {st_mode=S_IFREG|0644, st_size=65628, ...}) = 0
open("/usr/local/etc/ardour3/ardour3_ui_dark.rc", O_RDONLY|O_LARGEFILE) = 11
access("/usr/local/etc/ardour3/ardour3_ui_dark.rc.ru_RU", F_OK) = -1 ENOENT (No such file or directory)
access("/usr/local/etc/ardour3/ardour3_ui_dark.rc.ru", F_OK) = -1 ENOENT (No such file or directory)
access("/usr/local/etc/ardour3/ardour3_ui_dark.rc.ru_RU", F_OK) = -1 ENOENT (No such file or directory)
access("/usr/local/etc/ardour3/ardour3_ui_dark.rc.ru", F_OK) = -1 ENOENT (No such file or directory)
stat64("/usr/local/etc/ardour3/ardour_system.rc", {st_mode=S_IFREG|0644, st_size=2328, ...}) = 0
stat64("/usr/local/etc/ardour3/ardour_system.rc", {st_mode=S_IFREG|0644, st_size=2328, ...}) = 0
stat64("/usr/local/etc/ardour3/ardour_system.rc", {st_mode=S_IFREG|0644, st_size=2328, ...}) = 0
stat64("/usr/local/etc/ardour3/ardour_system.rc", {st_mode=S_IFREG|0644, st_size=2328, ...}) = 0
open("/usr/local/etc/ardour3/ardour_system.rc", O_RDONLY|O_LARGEFILE) = 11
stat64("/home/avp/.config/ardour3/ardour.rc", {st_mode=S_IFREG|0644, st_size=7122, ...}) = 0
stat64("/home/avp/.config/ardour3/ardour.rc", {st_mode=S_IFREG|0644, st_size=7122, ...}) = 0
stat64("/home/avp/.config/ardour3/ardour.rc", {st_mode=S_IFREG|0644, st_size=7122, ...}) = 0
stat64("/home/avp/.config/ardour3/ardour.rc", {st_mode=S_IFREG|0644, st_size=7122, ...}) = 0
open("/home/avp/.config/ardour3/ardour.rc", O_RDONLY|O_LARGEFILE) = 11
ardour: [INFO]: Loading system configuration file /usr/local/etc/ardour3/ardour_system.rc
Loading user configuration file /home/avp/.config/ardour3/ardour.rc