为什么编译信息长这样：

No valid executable file was produced by the compiler
/nix/store/p58l5qmzifl20qmjs3xfpl01f0mqlza2-binutils-2.40/bin/ld: /nix/store/gqghjch4p1s69sv4mcjksb2kb65rwqjy-glibc-2.38-23/lib/crt1.o: in function `_start':
(.text+0x1b): undefined reference to `main'
collect2: 错误：ld 返回 1