Bash snippet doesn't work in makefile

Question

I have one version file verfile which contains below version string
V1.1.2

And in Makefile I intend to read this version string, So I wrote Makefile as follows,

filepath        :=      $(PWD)
versionfile     :=      $(filepath)/verfile

all:
        cat $(versionfile)
        version=$(shell cat $(versionfile))
        echo "version=$(version)"

Now when I run the make file I get following ouput

cat /home/ubuntu/ankur/verfile
v1.1.2
version=v1.1.2
echo "version="
version=

So I am not able to store version string in the variable and use it later, I am not sure what am I doing wrong?

Any suggestion/pointer ?

After reading answer from "Didier Trosset" I changed my makefile as follows,

filepath        :=      $(PWD)
versionfile     :=      $(filepath)/verfile
myversion       :=      ""

all:

ifeq ($(wildcard $(versionfile)),)
all:
        echo "File not present"
else
all: myversion = $(shell cat $(versionfile))
endif
all:
        echo "myversion = $(myversion)"

and below is output for the

echo "myversion = v1.1.2"
myversion = v1.1.2

Answer 1

You have two problems. First to have bash (and not make) expand the variable you need to use $$version (or $${version}). By this Make first translates $$ into just $ and then bash will see $version (or ${version}). Secondly each line in the rule will be executed as a separate command, so in order to let them interact via environmental variables you have to put them into a common subshell, enclosing with paranthesis.

filepath        :=      $(PWD)
versionfile     :=      $(filepath)/verfile

all:
    cat $(versionfile)
    (version=$(shell cat $(versionfile)); echo "version=$$version")