What does numbers in make[1] make[2] make[3] mean?

Question

For example I get an error like this when running makefile:

make[3]: *** [/home/ziga/Downloads/openwrt/rakun_openwrt/staging_dir/host/stamp/.upx_installed] Error 1
make[2]: *** [tools/upx/install] Error 2
make[1]: *** [/home/ziga/Downloads/openwrt/rakun_openwrt/staging_dir/target-powerpc_uClibc-0.9.33.2/stamp/.tools_install_nynnn] Error 2

What does the number in the square brackets in make[3], make[2] and make[1]. I am not trying to solve this curent error. I am just curious about the syntax.

Answer 1

Basicly it shows the deepth of recursion