`make profile-fast` fails with "error: No $GIT_PERF_REPO defined, and your build directory is not a repo"

[Jan Keromnes <janx@xxxxxxxxx>]

Hello,

I'm trying to build a profile-optimized Git. I used to do this with
the following commands:

    mkdir /tmp/git
    cd /tmp/git
    curl https://www.kernel.org/pub/software/scm/git/git-2.13.3.tar.xz | tar xJ
    cd git-2.13.3
    make prefix=/usr profile man -j18
    sudo make prefix=/usr PROFILE=BUILD install install-man -j18

This worked fine. However, on some machines, the build takes more than
8 hours, so I'd like to use "profile-fast" instead of "profile":

    [...]
    make prefix=/usr profile-fast man -j18
    [...]

But this fails with the following error:

    ./run
    === Running 20 tests in this tree ===
    error: No $GIT_PERF_REPO defined, and your build directory is not a repo
    error: No $GIT_PERF_REPO defined, and your build directory is not a repo
    [...]
    error: No $GIT_PERF_REPO defined, and your build directory is not a repo
    cannot open test-results/p0000-perf-lib-sanity.subtests: No such
file or directory at ./aggregate.perl line 78.
    make[2]: *** [perf] Error 2
    Makefile:7: recipe for target 'perf' failed
    make[2]: Leaving directory '/tmp/git/git-2.13.3/t/perf'
    Makefile:2325: recipe for target 'perf' failed
    make[1]: *** [perf] Error 2
    make[1]: Leaving directory '/tmp/git/git-2.13.3'
    Makefile:1719: recipe for target 'profile-fast' failed
    make: *** [profile-fast] Error 2

The following thread gives me the impression that a similar problem
was already fixed for `make profile`:

http://git.661346.n2.nabble.com/make-profile-issue-on-Git-2-1-0-td7616964.html

Is it possible that the above commit fixed `make profile`, but not
`make profile-fast`?

Or, is there a good way for me to work around this issue?

Many thanks,
Jan Keromnes