makefile setting a variable in if statement in a target - makefile

Question

I have a Makefile with the following:
AVAR=""
all :
if [ -d ../old ]; then \
(echo "$# Ping!"; AVAR="../old"; echo $(AVAR)) \
fi
#echo $(AVAR)
The idea is that depending on the presence of directory "../old" i will or not
have information in AVAR (available for use later), however, the if is evaluating to true, and the Ping! is echoed, but nothing is assigned to AVAR, either inside or outside the if statement.
Output is as follows:
$ make all
if [ -d ../old ]; then \
(echo "all Ping!"; AVAR="../old"; echo "") \
fi
all Ping!
Any Insight appreciated.

Answer 1

1) Each command in a makefile recipe runs in its own subshell. You define AVAR in the first command (the "if" statement), so it's not available to the second command (#echo $(AVAR)).
2) Within the first command, you define AVAR, but you don't call it right. The term $(AVAR) is Make syntax; Make expands it before executing the command, and since Make doesn't know anything about such a variable, it expands to nothing. You have to use the shell to expand it, using shell syntax: $AVAR. But if you try that, Make will expand the $A to nothing, and you'll get "VAR". So you "escape" the $ with another $:
all :
if [ -d ../old ]; then \
(echo "$# Ping!"; AVAR="../old"; echo $$AVAR) \
fi

Answer 2

Try
(echo "$# Ping!"; AVAR="../old"; echo $$AVAR) \
instead of
(echo "$# Ping!"; AVAR="../old"; echo $(AVAR)) \

Answer 3

That may be a bit late, but in case someone else has the same question.
The way I handle it is by evaluating the if in a shell function and extract the stdout to a variable that's usable in the next command.
Method 1: appending the echo to the AVAR setting
if [ -d ../old ]; then \
(echo "$# Ping!") \
fi
AVAR=$(shell if [ -d ../old ]; then \
(AVAR="../old"; echo $${AVAR}) \
fi;) && \
echo $${AVAR}
or Method 2: evaluating the variable so that it could be used throughout the target without appending the echo ${AVAR} to the same shell.
if [ -d ../old ]; then \
(echo "$# Ping!") \
fi
$(eval AVAR=$(shell if [ -d ../old ]; then \
(AVAR="../old"; echo $${AVAR}) \
fi;))
#echo ${AVAR}
instead of
if [ -d ../old ]; then \
(echo "$# Ping!"; AVAR="../old"; echo $(AVAR)) \
fi
#echo $(AVAR)
Notes:
- AVAR being set by the $(shell ... ) output is a different variable from the one inside the if condition
- If you want to use a single if, you'll have to remove the stdout of "$# ping" from the beginning of AVAR content

Answer 4

Problem solved, Did the very bad recursive make option to redefine stuff and reinterpret.