Applied this patch:
http://gcc.gnu.org/r221947 Johann * config/avr/driver-avr.c (avr_devicespecs_file): Don't specify a device specs file if "device-specs%s" didn't resolve to a path. Index: config/avr/driver-avr.c =================================================================== --- config/avr/driver-avr.c (revision 221946) +++ config/avr/driver-avr.c (working copy) @@ -80,6 +80,19 @@ avr_devicespecs_file (int argc, const ch return X_NODEVLIB; case 1: + if (0 == strcmp ("device-specs", argv[0])) + { + /* FIXME: This means "device-specs%s" from avr.h:DRIVER_SELF_SPECS + has not been resolved to a path. That case can occur when the + c++ testsuite is run from the build directory. DejaGNU's + libgloss.exp:get_multilibs runs $compiler without -B, i.e.runs + xgcc without specifying a prefix. Without any prefix, there is + no means to find out where the specs files might be located. + get_multilibs runs xgcc --print-multi-lib, hence we don't actually + need information form a specs file and may skip it here. */ + return X_NODEVLIB; + } + mmcu = AVR_MMCU_DEFAULT; break;