山本です。bcc32 でも testrb test を最後まで実行できたので、報告します。

lib/drb/drb.rb に取り込んでいただいたパッチで testrb test/drb は通るように
なったんですが、testrb test だと test/drb の後のユニットで 
「開けるファイル数 50」の制限に達してしまって、そのままでは継続
できませんでした。

そこで、一時的に DRbConn::POOL_SIZE を 0 にしてテストした結果です。

E:\ruby_1_8\bin>ruby -v
ruby 1.8.2 (2004-07-22) [i386-bccwin32]

E:\ruby_1_8\bin>testrb e:/ruby-cvs/ruby_1_8/test
Loaded suite test
Started
.....E.....................FF...................................................
................................................................................
................................................................................
.......................................................................F........
................................................................................
....F.F...............................................................basic_auth
 is not supported under soap4r + net/http for now.
................................................................................
................................................................................
.............................................................................rex
ml cannot handle euc-jp without iconv/uconv.
................................................................................
..
Finished in 1105.993 seconds.

  1) Error:
test_IOReader_s_create_binmode(TestCSV):
CSV::IllegalFormatError: CSV::IllegalFormatError
    E:/ruby_1_8/lib/ruby/1.8/csv.rb:639:in `get_row'
    E:/ruby_1_8/lib/ruby/1.8/csv.rb:567:in `shift'
    e:/ruby-cvs/ruby_1_8/test/csv/test_csv.rb:307:in `test_IOReader_s_create_bin
mode'

  2) Failure:
test_macCR(TestCSV) [e:/ruby-cvs/ruby_1_8/test/csv/test_csv.rb:1158]:
<[["Avenches", "aus Umgebung"], ["Bad Hersfeld", "Ausgrabung"]]> expected but wa
s
<[["Avenches", "aus Umgebung\"Bad Hersfeld", "Ausgrabung"]]>.

  3) Failure:
test_s_foreach(TestCSV) [e:/ruby-cvs/ruby_1_8/test/csv/test_csv.rb:1734]:
<[["1", "2", "3"], ["4", "5", "6"]]> expected but was
<[["1", "2", "34", "5", "6"]]>.

  4) Failure:
test_precision(TestFloat) [e:/ruby-cvs/ruby_1_8/test/ruby/test_float.rb:46]:
<3.75176750364613e+17> expected but was
<3.75176750364613e+17>.

  5) Failure:
test_eof_0(TestPipe)
    [e:/ruby-cvs/ruby_1_8/test/ruby/ut_eof.rb:9:in `test_eof_0'
     e:/ruby-cvs/ruby_1_8/test/ruby/ut_eof.rb:5:in `open_file'
     e:/ruby-cvs/ruby_1_8/test/ruby/ut_eof.rb:5:in `test_eof_0']:
<nil> expected but was
<"">.

  6) Failure:
test_eof_1(TestPipe)
    [e:/ruby-cvs/ruby_1_8/test/ruby/ut_eof.rb:46:in `test_eof_1'
     e:/ruby-cvs/ruby_1_8/test/ruby/ut_eof.rb:40:in `open_file'
     e:/ruby-cvs/ruby_1_8/test/ruby/ut_eof.rb:40:in `test_eof_1']:
<nil> expected but was
<"">.

789 tests, 8349 assertions, 5 failures, 1 errors

1) .. 3) は bcc32 のテキストモードの挙動、
5) .. 6) は bcc32 の {read,fread} が ERROR_BROKEN_PIPE を扱ってないためですが、
4) は・・・？（testrb test/ruby では現れなかったので、気づきませんでした）

上の表示では違いがわからなかったので

Index: test_float.rb
===================================================================
RCS file: /var/cvs/src/ruby/test/ruby/test_float.rb,v
retrieving revision 1.5.2.4
diff -u -w -b -p -r1.5.2.4 test_float.rb
--- test_float.rb	14 Jul 2004 03:32:20 -0000	1.5.2.4
+++ test_float.rb	22 Jul 2004 04:39:23 -0000
@@ -43,7 +43,7 @@ class TestFloat < Test::Unit::TestCase
     #s = "3.7517675036461267e+17"
     #assert(s == sprintf("%.16e", s.to_f))
     f = 3.7517675036461267e+17
-    assert_equal(f, sprintf("%.16e", f).to_f)
+    assert_equal(0.0, f - sprintf("%.16e", f).to_f)
   end
 
   def test_symmetry_bignum # [ruby-bugs-ja:118]

とすると、

  4) Failure:
test_precision(TestFloat) [e:/ruby-cvs/ruby_1_8/test/ruby/test_float.rb:46]:
<0.0> expected but was
<64.0>.

と表示されました。