On Fri, 9 Feb 2018, Philip Oakley wrote:
> From: "Robert P. J. Day" <rpjday@xxxxxxxxxxxxxx>
> > On Fri, 9 Feb 2018, Philip Oakley, CEng MIET wrote:
> (apologies for using the fancy letters after the name ID...)
> >
> >> From: "Robert P. J. Day" <rpjday@xxxxxxxxxxxxxx>
> >> >
> >> > writing a short tutorial on "git bisect" and, all the details
> >> > of special exit code 125 aside, if one wanted to locate the
> >> > first unbuildable commit, would it be sufficient to just run?
> >> >
> >> > $ git bisect run make
> >> >
> >> > as i read it, make returns either 0, 1 or 2 so there doesn't
> >> > appear to be any possibility of weirdness with clashing with a
> >> > 125 exit code. am i overlooking some subtle detail here i
> >> > should be aware of? thanks.
> >> >
> >> > rday
> >>
> >> In the spirit of pedanticism, one should also clarify the word
> >> "first", in that it's not a linear search for _an_ unbuildable
> >> commit, but that one is looking for the transition between an
> >> unbroken sequence of unbuildable commits, which transitions to
> >> buildable commits, and its the transition that is sought. (there
> >> could be many random unbuildable commits within a sequence in
> >> some folks' processes!)
> >
> > quite so, i should have been more precise.
> >
> > rday
>
> The other two things that may be happening (in the wider bisect
> discussion) that I've heard of are:
> 1. there may be feature branches that bypass the known good starting
> commit, which can cause understanding issues as those side
> branches that predate the start point are also considered
> potential bu commits.
... snip ...
sorry, i should have replied to this post since my last post
directly addresses this scenario -- i believe this is precisely what
you were suggesting:
... 50000 commits ... (feature branch)
/ ^
/ \
v \
A <-- B <-- <GOOD> <-- D <-- E <-- F <-- <BAD>
i'm still curious ... if one doesn't get into skipping, what is the
"git rev-list" command to identify all of the possible revisions to be
tested here? isn't it just:
$ git rev-list <BAD> ^<GOOD>
or was there somthing more subtle i was missing? sorry if someone
already explained this, i'll go back later and read the replies in
more excruciating detail.
rday
p.s. i'll take a closer look at the "--bisect*" options to "git
rev-list" shortly.
