[perl #122649] Unneeded rebuilds on rakudo-moar

[Christian Bartolomaeus via RT]

This happens for all backends. AFAIU the reason is that we have a target 
m-runner-default (in the case of Moar) in our Makefile. This target is a 
dependency for target all and is therefore called when executing make. But 
since there is no file m-runner-default this target is considered out of date 
by make and the commands are executed always. The relevant lines from 
Makefile:

all: m-all m-runner-default
[...]
m-runner-default: $(M_RUNNER)
$(RM_F) perl6
-$(CP) $(M_RUNNER) perl6
-$(CHMOD) 755 perl6

I think we could get around this with using the actual executable perl6 as 
the target:

M_RUNNER_DEFAULT = perl6
all: m-all $(M_RUNNER_DEFAULT)
[...]
$(M_RUNNER_DEFAULT): $(M_RUNNER)
$(RM_F) perl6
-$(CP) $(M_RUNNER) perl6
-$(CHMOD) 755 perl6

But I don't know a) if there is a reason for curren behaviour and b) if it's 
worth the trouble. Looks like the functionality was added by moritz about a 
year ago (for Parrot and JVM): 
https://github.com/rakudo/rakudo/commit/af43daed4746b2c5678e3de82ca2926d254e6906

[perl #122649] Unneeded rebuilds on rakudo-moar

[via RT]

# New Ticket Created by  Will Coleda 
# Please include the string:  [perl #122649]
# in the subject line of all future correspondence about this issue. 
# URL: https://rt.perl.org/Ticket/Display.html?id=122649 


after a build:

$ make
/opt/local/bin/perl5.16 -MExtUtils::Command -e rm_f perl6
/opt/local/bin/perl5.16 -MExtUtils::Command -e cp perl6-m perl6
/opt/local/bin/perl5.16 -MExtUtils::Command -e chmod 755 perl6
~/sandbox/rakudo
$ make
/opt/local/bin/perl5.16 -MExtUtils::Command -e rm_f perl6
/opt/local/bin/perl5.16 -MExtUtils::Command -e cp perl6-m perl6
/opt/local/bin/perl5.16 -MExtUtils::Command -e chmod 755 perl6
~/sandbox/rakudo

./perl6 is continually remade.

-- 
Will Coke Coleda