I want to test the profile usage of an important library-class of my rails-project. It uses ActiveRecord so I need all rails dependencies to profile it.

As far as I know, I need a patched ruby (rubygc) so script/profile and script/benchmark can track memory usage. I tried to follow this official guide to patch the source code of ruby 1.8.6 (p399) and 1.8.7 (p248), but both fail with the following message:

patching file gc.c
Hunk #2 succeeded at 50 with fuzz 2 (offset 2 lines).
Hunk #3 succeeded at 87 with fuzz 2 (offset 6 lines).
Hunk #4 succeeded at 153 with fuzz 1 (offset 45 lines).
Hunk #5 succeeded at 409 with fuzz 2 (offset 274 lines).
Hunk #6 FAILED at 462.
Hunk #7 FAILED at 506.
Hunk #8 FAILED at 520.
Hunk #9 FAILED at 745.
Hunk #10 FAILED at 754.
Hunk #11 FAILED at 923.
Hunk #12 succeeded at 711 (offset 46 lines).
Hunk #13 succeeded at 730 (offset 46 lines).
Hunk #14 succeeded at 766 (offset 55 lines).
Hunk #15 succeeded at 1428 (offset 87 lines).
Hunk #16 succeeded at 1492 (offset 89 lines).
Hunk #17 FAILED at 1541.
Hunk #18 FAILED at 1551.
Hunk #19 succeeded at 1571 (offset 91 lines).
Hunk #20 succeeded at 1592 (offset 91 lines).
Hunk #21 succeeded at 1601 (offset 91 lines).
Hunk #22 succeeded at 1826 (offset 108 lines).
Hunk #23 succeeded at 1843 (offset 108 lines).
Hunk #24 succeeded at 1926 (offset 108 lines).
Hunk #25 succeeded at 2118 (offset 108 lines).
Hunk #26 succeeded at 2563 (offset 100 lines).
Hunk #27 succeeded at 2611 with fuzz 1 (offset 102 lines).
Hunk #28 succeeded at 2628 (offset 102 lines).
8 out of 28 hunks FAILED -- saving rejects to file gc.c.rej
patching file intern.h
Hunk #1 succeeded at 268 (offset 15 lines).

I also tried to use ruby-prof, but I always get the error "uninitialized constant RubyProf::Test". I don't know how to use the gem "memory" and neither "memprof" nor "bleak_house" could be installed successfully.

If I get a patched ruby running, I should be fine. But any other possibility to profile the memory of library classes are welcome. Thanks for helping!