Re: mwrap and Ruby 2.6.5

[Eric Wong <e@yhbt.net>]

Grzegorz Daniluk <gdaniluk@gmail.com> wrote:
> Hi Eric,
> 
> Does mwrap work with Ruby 2.6.5?

Yes, it should work on all 2.6, but I'm not sure how rbenv
configures it...  Judging from libruby.so.2.6 addresses in your
log it could be with --enable-shared, which isn't the default

I've always just built using `./configure && make ...' and never
bothered with rvm/rbenv stuff.  I no longer have access to
hardware capable of building extra Rubies in a reasonable amount
of time, though, so my ability to test alternate builds is
limited.

> I tried to use mwrap from the Gem, it works however there are no Ruby
> code line numbers in the output. Memory leaks are reported at places
> like libruby.so.2.6(+0xdb97f). I downloaded the git repo and tried to
> run the tests, not all tests passed, please see the attached file.

Thanks for sharing the log, comments inline.

> greg@amd:~/dev/mwrap$ rake test
> install -c tmp/x86_64-linux/mwrap/2.6.5/mwrap.so lib/mwrap.so
> cp tmp/x86_64-linux/mwrap/2.6.5/mwrap.so tmp/x86_64-linux/stage/lib/mwrap.so
> Loaded suite /home/greg/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/rake-13.0.1/lib/rake/rake_test_loader
> Started
> Traceback (most recent call last):
> -e:5:in `<main>': undefined method `each' for nil:NilClass (NoMethodError)

I guess `-e loc=Mwrap["-e:3"]' on the command-line failed,
probably because of libruby being a shared library.

> ========================================================================================================================
>      179:       -e loc.each{|size,gen|p([size,gen,count])}
>      180:     )
>      181:     buf = IO.popen(@@env, cmd, &:read)
>   => 182:     assert_predicate $?, :success?
>      183:     assert_match(/\A\[\s*\d+,\s*\d+,\s*\d+\]\s*\z/s, buf)
>      184:     size, gen, count = eval(buf)
>      185:     assert_operator size, :>=, 10000
> /home/greg/dev/mwrap/test/test_mwrap.rb:182:in `test_aref_each'
> Failure: test_aref_each(TestMwrap):
>   <#<Process::Status: pid 8817 exit 1>>.success? is true value expected but was
>   <false>

> ========================================================================================================================
> F
> ========================================================================================================================
> /home/greg/dev/mwrap/test/test_mwrap.rb:94:in `test_clear'
> /home/greg/.rbenv/versions/2.6.5/lib/ruby/2.6.0/tempfile.rb:336:in `create'
>       98:       tmp.rewind
>       99:       buf = tmp.read
>      100:       assert_not_match(/\s+-e:1$/, buf)
>   => 101:       assert_match(/\b20001\s+1\s+-e:3$/, buf)
>      102:     end
>      103:   end
>      104: 
> /home/greg/dev/mwrap/test/test_mwrap.rb:101:in `block in test_clear'
> Failure: test_clear(TestMwrap):
>   </\b20001\s+1\s+-e:3$/> was expected to be =~
>   <"           20001            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xe0e64) [0x7f5f8a0d7e64]\n">.

Yeah, I wonder if the tests need to be relaxed or skipped for
builds with shared libraries.

> ========================================================================================================================
> .F
> ========================================================================================================================
> /home/greg/dev/mwrap/test/test_mwrap.rb:40:in `test_dump_via_destructor'
> /home/greg/.rbenv/versions/2.6.5/lib/ruby/2.6.0/tempfile.rb:336:in `create'
>      42:       res = system(env, *cmd, { 5 => tmp })
>      43:       assert res, $?.inspect
>      44:       tmp.rewind
>   => 45:       assert_match(/\b10001\s+1\s+-e:1$/, tmp.read)
>      46: 
>      47:       env['MWRAP'] = 'dump_fd:1,dump_min:10000'
>      48:       tmp.rewind
> /home/greg/dev/mwrap/test/test_mwrap.rb:45:in `block in test_dump_via_destructor'
> Failure: test_dump_via_destructor(TestMwrap):
>   </\b10001\s+1\s+-e:1$/> was expected to be =~
>   <"             120            1 /lib/x86_64-linux-gnu/libc.so.6(+0x2ec3e) [0x7f4bc5380c3e]\n" +
>   "           13440            7 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(rb_encdb_replicate+0x288) [0x7f4bc57e5438]\n" +
>   "             192            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xddd68) [0x7f4bc5820d68]\n" +
>   "         1723566         3807 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xe0e64) [0x7f4bc5823e64]\n" +
>   "             208            1 /lib/x86_64-linux-gnu/libc.so.6(+0x2c740) [0x7f4bc537e740]\n" +
>   "             384            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xa14e1) [0x7f4bc57e44e1]\n" +
>   "             171            1 /lib/x86_64-linux-gnu/libc.so.6(+0x2ceea) [0x7f4bc537eeea]\n" +
>   "            3728           12 /lib/x86_64-linux-gnu/libc.so.6(+0x2e1e1) [0x7f4bc53801e1]\n" +
>   "             640            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(ruby_init_setproctitle+0x68) [0x7f4bc59c2ec8]\n" +
>   "            1344            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0x25e120) [0x7f4bc59a1120]\n" +
>   "              32            1 /lib/x86_64-linux-gnu/libpthread.so.0(pthread_getattr_np+0xf5) [0x7f4bc456b515]\n" +
>   "             240            1 /lib/x86_64-linux-gnu/libc.so.6(getdelim+0x148) [0x7f4bc53d1be8]\n" +
>   "             552            1 /lib/x86_64-linux-gnu/libc.so.6(fopen+0x1a) [0x7f4bc53d0e4a]\n" +
>   "             544            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xd8d93) [0x7f4bc581bd93]\n" +
>   "             120            1 /lib/x86_64-linux-gnu/libc.so.6(getdelim+0xec) [0x7f4bc53d1b8c]\n" +
>   "             156            2 /lib64/ld-linux-x86-64.so.2(+0x1d32a) [0x7f4bc5eee32a]\n" +
>   "            1024            1 /lib/x86_64-linux-gnu/libc.so.6(_IO_file_doallocate+0x8c) [0x7f4bc53d018c]\n" +
>   "              24            2 /lib/x86_64-linux-gnu/libc.so.6(__strdup+0x1a) [0x7f4bc53ef9ba]\n" +
>   "             128            1 /usr/lib/x86_64-linux-gnu/liburcu-bp.so.6(+0x273d) [0x7f4bc4f4873d]\n" +
>   "             520            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0x25e12d) [0x7f4bc59a112d]\n" +
>   "           81920            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0x259080) [0x7f4bc599c080]\n" +
>   "             304            1 /lib64/ld-linux-x86-64.so.2(_dl_allocate_tls+0x27) [0x7f4bc5ee44a7]\n" +
>   "           16032            4 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xddcd5) [0x7f4bc5820cd5]\n" +
>   "            6423          113 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(ruby_xrealloc2+0x6c) [0x7f4bc582799c]\n" +
>   "               5            1 /lib/x86_64-linux-gnu/libc.so.6(+0x35240) [0x7f4bc5387240]\n" +
>   "             712            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0x9352e) [0x7f4bc57d652e]\n" +
>   "            3456            4 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(rb_encdb_declare+0x1e8) [0x7f4bc57e4ce8]\n" +
>   "               8            1 /lib/x86_64-linux-gnu/librt.so.1(timer_create+0x56) [0x7f4bc435e2f6]\n" +
>   "             176            1 /lib64/ld-linux-x86-64.so.2(+0x14463) [0x7f4bc5ee5463]\n" +
>   "        33554432            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xde935) [0x7f4bc5821935]\n" +
>   "            8192            1 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0x241f92) [0x7f4bc5984f92]\n" +
>   "            2492            2 /lib64/ld-linux-x86-64.so.2(+0xc101) [0x7f4bc5edd101]\n" +
>   "              32            1 /lib/x86_64-linux-gnu/libc.so.6(+0xcbea8) [0x7f4bc541dea8]\n" +
>   "          373480         4365 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(ruby_xcalloc+0x5c) [0x7f4bc58275bc]\n" +
>   "             208            1 /lib/x86_64-linux-gnu/libc.so.6(+0x2c457) [0x7f4bc537e457]\n" +
>   "             536            3 /lib64/ld-linux-x86-64.so.2(+0xe90e) [0x7f4bc5edf90e]\n" +
>   "            6720           24 /home/greg/.rbenv/versions/2.6.5/lib/libruby.so.2.6(+0xdd8f7) [0x7f4bc58208f7]\n" +
>   "             156            2 /lib64/ld-linux-x86-64.so.2(+0xc3e8) [0x7f4bc5edd3e8]\n">.
> ========================================================================================================================

Odd, no match 10001 in the above at all.  I wonder if that's a
separate issue, since Ruby could theoretically request extra
space.  I admit some of these tests are fragile and may be
worth skipping or removing.

> ...E
> ========================================================================================================================
> /home/greg/dev/mwrap/test/test_mwrap.rb:25:in `test_mwrap_preload'
> /home/greg/.rbenv/versions/2.6.5/lib/ruby/2.6.0/tempfile.rb:336:in `create'
>      28:       assert res, $?.inspect
>      29:       tmp.rewind
>      30:       lines = tmp.readlines

`pp lines' here might give some insight on whether there's
a `10001' match at all.

>   => 31:       line_1 = lines.grep(/\s-e:1\b/)[0].strip
>      32:       assert_equal '10001', line_1.split(/\s+/)[0]
>      33:     end
>      34:   end
> /home/greg/dev/mwrap/test/test_mwrap.rb:31:in `block in test_mwrap_preload'
> Error: test_mwrap_preload(TestMwrap): NoMethodError: undefined method `strip' for nil:NilClass
> ========================================================================================================================
> ....Traceback (most recent call last):
> /tmp/mwrap20200322-8815-172sjvz.rb:5:in `<main>': undefined method `name' for nil:NilClass (NoMethodError)
> ========================================================================================================================
>      221:   end
>      222: 
>      223:   def test_source_location
>   => 224:     assert_separately(+"#{<<~"begin;"}\n#{<<~'end;'}")
>      225:     begin;
>      226:       require 'mwrap'
>      227:       foo = '0' * 10000
> /home/greg/dev/mwrap/test/test_mwrap.rb:224:in `test_source_location'
> /home/greg/dev/mwrap/test/test_mwrap.rb:216:in `assert_separately'
> /home/greg/.rbenv/versions/2.6.5/lib/ruby/2.6.0/tempfile.rb:336:in `create'
> /home/greg/dev/mwrap/test/test_mwrap.rb:219:in `block in assert_separately'
> Failure: test_source_location(TestMwrap): <false> is not true.
> ========================================================================================================================

Dunno, but probably related o the other errors.

> .
> Finished in 0.393798954 seconds.
> ------------------------------------------------------------------------------------------------------------------------
> 14 tests, 80 assertions, 4 failures, 1 errors, 0 pendings, 0 omissions, 0 notifications
> 64.2857% passed

At least some stuff passed, so it's probably down to fragile
tests not being compatible with shared library builds.

I basically rely on `warn foo.inspect' or `pp' to diagnose
things.  It may be worth the time to make them pass, when shared
builds are detected, but maybe skipping them is easier, for now.