https://bugs.gentoo.org/745291

--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 DRIVER_DIR=${DESTDIR}/${USBDROPDIR}/ifd-ASEKey.bundle
 UDEV_DIR=${DESTDIR}/${UDEVDIR}
 
-CC=${BUILD}-gcc
+CC?=gcc
 
 SOURCES=usb.c atr.c DriverIO.c CommandTypes.c ReaderCommands.c T1Protocol.c MemoryCards.c InitCardParams.c ifdhandler.c