Re: export does not export to $(shell ...

[John Graham-Cumming]

Martin d'Anjou wrote:
> How do I convince export to export variables to $(shell ...)?
>
> l:=$(shell echo $$USER)
> $(warning $(l))
> export VAR=Hi
> l:=$(shell echo VAR $$VAR)
> $(warning $(l))
>
> all:
>         echo $$VAR
>
> Is this a bug? I use 3.81beta3

The code handling $(shell) (func_shell in function.c) uses the parent 
environment (from environ) for the sub-shell.  Hence GNU Make's export 
directive will not put GNU Make variables into the $(shell) environment.

You could have this like this:

    export FOO=fooey
    ORIGINAL := $(shell echo 1: $$FOO)
    HACKED := $(shell export FOO=$(FOO) ; echo 2: $$FOO)

    all:
        @echo Original: $(ORIGINAL)
        @echo Hacked:   $(HACKED)

John.
--
John Graham-Cumming
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