Why is there such error of "arm-linux-gcc: not found"?

For building u-boot of my board, I followed below two commands as told: $ sudo make nanopi_h3_defconfig ARCH=arm CROSS_COMPILE=arm-linux- $ sudo make ARCH=arm CROSS_COMPILE=arm-linux- I got the result from the 1st command: **configuration written to .config** It means success. But got the below from the 2nd command: make: arm-linux-gcc: No such file or directory /bin/sh: 1: arm-linux-gcc: not found dirname: missing operand Try 'dirname --help' for more information. scripts/kconfig/conf --silentoldconfig Kconfig ./scripts/binutils-version.sh: line 18: arm-linux-as: command not found CHK include/config.h CFG u-boot.cfg /bin/sh: 1: arm-linux-gcc: not found make: *** [scripts/Makefile.autoconf:79: u-boot.cfg] Error 1 make: *** No rule to make target 'include/config/auto.conf', needed by 'include/config/uboot.release'. Stop. It seems trouble coming from arm-linux-gcc, but I ran command 'arm-linux-gcc', it works. So, why can the first command pass through arm-linux-gcc, but the 2nd command failed?