Using Cygwin v3.5.3, Makefile (GNU Make v4.4.1) on Win11, I have a common canned recipe that is being called from various other targets with different variables.

MYDate = date -u +'$1: %d-%m-%Y %H:%M:%S'
define cand-recipe =
    $(call MYDate, $(var1))
    $ echo -e "nIn the canned recipe"
    $ rsync -aqh $(sdir) $(ddir) 2> $(elog)
endef

I call this canned recipe with targets like:

mytarget: var1 := some value
mytarget: sdir := $(SRCDir)
mytarget: ddir := $(DSTDir)
mytarget: elog := $(ERRlogfile)
mytarget:
    $(cand-recipe)

All this is working fine but if I try to add more info with if-else bash statements or process error log then make reports syntax errors or reports error:

*** prerequisites cannot be defined in recipes. Stop.

MYDate = date -u +'$1: %d-%m-%Y %H:%M:%S'
define cand-recipe =
    $(call MYDate, $(var1))
    $ echo -e "nIn the canned recipe"
    $ rsync -aqh $(sdir) $(ddir) 2> $(elog)
    $ if [ -s $(elog) ]; then
        $ $(call MYDate, ERROR:);
        $ $(eval elogvar := $(file < $(elog)));
        $ echo -e "n$(elogvar)n";
        $ $(file >> $(elog),$(call MYDate, ERROR:));
    fi
endef

I’m just trying to read the elog file. If this error log file is NOT empty then I print date on terminal, put the contents of the error log file into a variable, print the contents of error log file on terminal and append the date to the error log file.