Makefile: Parent - Child Inheritance and export

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# 1  
Old 09-30-2009
Makefile: Parent - Child Inheritance and export


I have a number of Makefiles, including a couple of files that I include in Makefiles, a few scripts that are executed through Makefiles, and I have problems with environment variables that are not inherited to the scripts properly.

Simplified scenario:


     ${MAKE} -C mk alla


export TARGET:= x86

include rootdir/mk/

       @echo I am in mk/Makefile


$(shell ./



echo Target is: $TARGET  1>&2

And when I run rootdir/Makefile

I get

Target is:
I am in mk/Makefile

that is, the shell script did not inherit the TARGET environment variable.
However, if I put the export TARGET:= x86 in the root/Makefile instead, then the shell script does inherit the TARGET environment variable, i.e.

Target is: x86
I am in mk/Makefile

Why is that? And what is the solution?

I think I do understand that export will spawn a new child process, thus the makefile where the export is in, can not see it, which is also true for the include as it expands the But I thought that when you run a script, it will also create a child process and it will inherit the export environment variable??

Thanks in advance!
# 2  
Old 10-06-2009
If anyone is interested, it is apparently a bug in Makefile, and there is no complete solution. However, in my case, I could pass the environment variable to $(shell) and the script would then have access to it.

$(shell TARGET=$(TARGET) ./
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