However the binaries(cd, umask, wait) that cause problem are not dependency of s6.
Those binaries are not causing problems. What *is* causing problems is fellow developers who *think* those binaries are problematic, for reasons that all come from ignorance of how Unix (and the shell) works. This is, as you have stated, a political issue. It is not a technical issue, and in particular, it is not a technical issue with execline. So, please avoid framing it as if it was. I totally understand your predicament, but I unfortunately have no good solution for you, except "educate your peers". Political problems are not solved with technical fixes, and when you try to do so, not only do you not entirely fix the political problems, but you also add technical problems on top. This never ends well. -- Laurent