From: "Philip Oakley" <philipoakley@xxxxxxx>
Sent: Friday, June 26, 2015 12:34 AM
From: "Junio C Hamano" <gitster@xxxxxxxxx>
"Philip Oakley" <philipoakley@xxxxxxx> writes:
From: "Junio C Hamano" <gitster@xxxxxxxxx>
I am not sure what this patch is trying to achieve.
I have been able to repeat the issue, more below.
It was probably a bit of 'don't mess with working code', given that
I'd used the NO_PERL solution, rather 'document the issue'....
Then this part applies, I think.
If you are not touching what this Makefile actually does, then I
would imagine that you are running the "buildsystems code" that
actually drives 'make -n' with some "available solution" (perhaps
you are running 'make -n NO_PERL=NoThanks' or something like that)?
Then instead of a command like this that nobody would read in this
file, the same command can instead go there to explain what the
"workaround" (e.g. unusual-looking 'make -n NO_PERL=NoThanks') is
doing?
The command sequence:
$ git clean -dfx
$ make -n MSVC=1 V=1 2>ErrsFile.txt 1>MakeDry.txt
produces the error
make[1]: *** No rule to make target 'PM.stamp', needed by 'perl.mak'.
Stop.
make: *** [perl/perl.mak] Error 2
the actual MakeDry.txt reaches
echo "$FLAGS" >GIT-CFLAGS; \
fi
make[2]: Leaving directory '/c/msysgit195/git'
make[1]: Leaving directory '/c/msysgit195/git/perl'
Makefile:1758: recipe for target 'perl/perl.mak' failed
My understanding of the error is that, first, the PM.stamp is removed by
the clean, then the dryrun has by the error time passed the initial
PM.stamp update code, but doesn't execute it (being a dry run), thus the
file PM.stamp still does not exist.
The makefile then descends into the 'perl/Makefile' pre-requisite to
'perl/perl.mak', and (IIUC) at this point the L25#$(makfile): PM.stamp
then barfs because there is no PM.stamp to be a prerequisite for that
line.
As noted in the patch, my response at the time (not fully understanding
why) was simply to annotate the Makefile's PM.stamp (which is where the
error would first leads any future debugging).
Possibly other options would be to add an extra PM.stamp target which,
for a dry-run (+recipe), creates any empty PM.stamp file if one does not
exist, simply to allow the perl/perl.mak to succeed. Or perhaps simply
add the PM.stamp file to the code (or maybe not).
A third option would be to simply convert the PM.stamp recipe to a
+recipe so that it's executed during the dry-run, but that may be
contrary to the idea of being a dry-run.
Do you have any preference for how I should resolve this? Ideally I like
to drop the use of the NO_PERL in the dry run.
--
Philip
I was more of the view that this was about prevention (here), rather
than retrospective explanation of the code (there).
In my case the errors were showing problems with the PM.stamp in the
makefile (I didn't have the solution at that point).
So either a short comment "# consider using 'NO_PERL=YesPlease' for
dry
run invocations" (beware your double negative ;-), or the addition of
the '+recipe', would still be my preferred change, rather than leaving
the open manhole for others to fall into.
The thread on my difficulties is at $gmane/263656 (2015-02-10 22:51)
"
At the moment I'm getting (on my old WinXP machine, using Msysgit
1.9.5 as a basis)
$ make -n MSVC=1 V=1 1>makedry.txt
make[1]: *** No rule to make target `PM.stamp', needed by
`perl.mak'.
Stop.
make: *** [perl/perl.mak] Error 2
"
As you can see, at that time the place to look would be the makefile,
so I would do think a 'fix' there would still be appropriate.
Do you have a preference among the three options (comment, +recipe,
drop)?
--
Philip
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