A problem when building u-boot-xlnx

[yonghaoXuGit]

When I execute "make arm-uboot" command,I encounter the problem:errno: TLS definition in //home/linuxbrew/.linuxbrew/Cellar/glibc/2.23/lib/libc.so.6 section .tbss mismatches non-TLS reference in /tmp/ccWHlgwX.o
/home/linuxbrew/.linuxbrew/bin/ld: //home/linuxbrew/.linuxbrew/Cellar/glibc/2.23/lib/libc.so.6: error adding symbols: bad value
After debugging,I find a global variable was declared in include/errno.h.What's the reason?Any method can solve it.
Thanks!

[yonghaoXuGit]

But when I chang the "extern int errno" to "int errno" in errno.h,the problem change to common/env_sf.o: In function env_init': /home/whut/xuyonghao/RISCV/test/fpga-zynq/common/u-boot-xlnx/common/env_sf.c:221: multiple definition of errno'
common/env_attr.o:/home/whut/xuyonghao/RISCV/test/fpga-zynq/common/u-boot-xlnx/common/env_attr.c:30: first defined here