Re: Change the default shell from an environment variable

[Paul Smith]

On Sun, 2021-07-25 at 23:51 +0900, Masahiro Yamada wrote:
> But, since it is not possible to propagate SHELL
> down to sub-makes, we end up with adding the same setup:
> 
>    SHELL := /bin/bash
> 
> in every sub-makefiles.

You could do something like this instead:

  SHELL := /bin/bash
  MAKEOVERRIDES += SHELL=/bin/bash

in the top-level makefile, then it would get passed to all sub-makes as
if you'd invoked "make SHELL=/bin/bash".

See 
https://www.gnu.org/software/make/manual/html_node/Options_002fRecursion.html