Description of problem:

Trying to rebuild icu from the srpm:
   icu-4.2.1-9.1.el6_2.src.rpm
downloaded from :
   ftp://ftp.redhat.com/pub/redhat/linux/enterprise/6Server/en/os/SRPMS/icu-4.2.1-9.1.el6_2.src.rpm

(which appears to be the latest available as of writing (@ 2014/12/19)

fails, with latest tzdata-2014j-1.el6.noarch timezone data, and having
just run 'system-config-language', to create /etc/sysconfig/i18n :

LANG="en_US.UTF-8"
SUPPORTED="en_US.UTF-8:en"
SYSFONT="lat0-sun16"
SYSFONTACM="iso01"

I have tried running this command :

 $ rpmbuild --rebuild ${SRPMS}/icu-4.2.1-9.1.el6_2.src.rpm \
            --define _topdir' '${PWD}
           ...

with various LANG and LC_ALL settings:
  
 $ LC_ALL=POSIX LANG=C  rpmbuild ...
 $ LC_ALL=POSIX LANG=en_US.UTF-8  rpmbuild ...
 $ LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8 rpmbuild ...

but the rpmbuild commands always fails in %check's:
<quote>
      make -C source check
</quote

with the error:

<quote>
Errors in total: 1.
            TestTwoDigitYear
         DateFormatTest
      format
</quote>

GDB shows the expected and actual results differ:
<code>
$ cd BUILD/icu/source/test/intltest/
$ export TZ=GMT
$ LD_LIBRARY_PATH=../../lib:../../stubdata:../../tools/ctestfw  gdb --args ./intltest 

(gdb) b dtfmttst.cpp:914
Breakpoint 1 at 0x49a0d3: file dtfmttst.cpp, line 914.
(gdb) run
Breakpoint 1, DateFormatTest::TestTwoDigitYear (this=0x7fffffffcb10) at dtfmttst.cpp:914
914         UErrorCode ec = U_ZERO_ERROR;
Missing separate debuginfos, use: debuginfo-install glibc-2.12-1.132.el6.4.x86_64
(gdb) n
915         SimpleDateFormat fmt("dd/MM/yy", Locale::getUK(), ec);
(gdb) 
913     {
(gdb) 
915         SimpleDateFormat fmt("dd/MM/yy", Locale::getUK(), ec);
(gdb) 
916         if (U_FAILURE(ec)) {
(gdb) 
920         parse2DigitYear(fmt, "5/6/17", date(117, UCAL_JUNE, 5));
(gdb) 
921         parse2DigitYear(fmt, "4/6/34", date(34, UCAL_JUNE, 4));
(gdb) s
CalendarTimeZoneTest::date (this=0x7fffffffcb10, y=34, m=5, d=4, hr=0, min=0, sec=0) at caltztst.cpp:182
182     {
(gdb) fin
Run till exit from #0  CalendarTimeZoneTest::date (this=0x7fffffffcb10, y=34, m=5, d=4, hr=0, min=0, sec=0) at caltztst.cpp:182
0x000000000049a1f9 in DateFormatTest::TestTwoDigitYear (this=0x7fffffffcb10) at dtfmttst.cpp:921
921         parse2DigitYear(fmt, "4/6/34", date(34, UCAL_JUNE, 4));
Value returned is $1 = -1122739200000
(gdb) s
DateFormatTest::parse2DigitYear (this=0x7fffffffcb10, fmt=..., str=0x69793b "4/6/34", expected=-1122739200000) at dtfmttst.cpp:928
928     {
(gdb) n
929         UErrorCode status = U_ZERO_ERROR;
(gdb) 
931             UDate d = fmt.parse(str, status);
(gdb) s
icu_4_2::UnicodeString::UnicodeString (this=0x7fffffffba80, codepageData=0x69793b "4/6/34") at unistr_cnv.cpp:42
42      UnicodeString::UnicodeString(const char *codepageData)
(gdb) fin
Run till exit from #0  icu_4_2::UnicodeString::UnicodeString (this=0x7fffffffba80, codepageData=0x69793b "4/6/34") at unistr_cnv.cpp:42
0x0000000000497f55 in DateFormatTest::parse2DigitYear (this=0x7fffffffcb10, fmt=..., str=0x69793b "4/6/34", expected=-1122739200000) at dtfmttst.cpp:931
931             UDate d = fmt.parse(str, status);
(gdb) s
icu_4_2::SimpleDateFormat::parse (this=0x7fffffffbb50, text=..., status=@0x7fffffffbabc) at smpdtfmt.cpp:2155
2155        return DateFormat::parse(text, status);
(gdb) s
icu_4_2::DateFormat::parse (this=0x7fffffffbb50, text=..., status=@0x7fffffffbabc) at datefmt.cpp:207
207     {
(gdb) n
208         if (U_FAILURE(status)) return 0;
(gdb) 
207     {
(gdb) 
219         return result;
(gdb) p result
$2 = <value optimized out>
(gdb) fin
Run till exit from #0  icu_4_2::DateFormat::parse (this=0x7fffffffbb50, text=..., status=@0x7fffffffbabc) at datefmt.cpp:219
0x0000000000497f66 in DateFormatTest::parse2DigitYear (this=0x7fffffffcb10, fmt=..., str=0x69793b "4/6/34", expected=-1122739200000) at dtfmttst.cpp:931
931             UDate d = fmt.parse(str, status);
Value returned is $3 = 2033017200000
(gdb) 
(gdb) info shared
From                To                  Syms Read   Shared Object Library
0x000000347b200b00  0x000000347b2198eb  Yes (*)     /lib64/ld-linux-x86-64.so.2
0x00007ffff7d73ce0  0x00007ffff7d78de8  Yes         ../../tools/ctestfw/libicutest.so.42
0x00007ffff7a38280  0x00007ffff7b1df58  Yes         ../../lib/libicui18n.so.42
0x00007ffff76c57e0  0x00007ffff7762268  Yes         ../../lib/libicuuc.so.42
0x00007ffff6540440  0x00007ffff6540548  Yes (*)     ../../lib/libicudata.so.42
0x00007ffff62fd4c0  0x00007ffff630cfe8  Yes         ../../lib/libicutu.so.42
0x000000302d605760  0x000000302d6110c8  Yes (*)     /lib64/libpthread.so.0
0x0000003038e56380  0x0000003038ec1c96  Yes         /usr/lib64/libstdc++.so.6
0x000000302ce03e70  0x000000302ce43fb8  Yes (*)     /lib64/libm.so.6
0x0000003037e028a0  0x0000003037e12da8  Yes         /lib64/libgcc_s.so.1
0x000000302ca1eaa0  0x000000302cb3ff4c  Yes (*)     /lib64/libc.so.6
</code>

Now, this is the date corresponding to time value 2033017200000 :

$ perl -MPOSIX -e 'print ctime(2033017200000);'
Fri Oct  1 16:00:00 66393

I am struggling to understand how the parser ends up with such a date
given the ASCII string "4/6/34" as input :

$ perl -MPOSIX -e '$t=mktime(0,0,0,4,5,34); print $t,": ",ctime($t);'
-1122768000: Mon Jun  4 00:00:00 1934

-1122768000 would be the correct "expected" value for the test, but the
test is expecting -1122739200000 :

$ perl -MPOSIX -e '$t=-1122739200000; print $t,": ",ctime($t);'
-1122739200000: Thu Oct 24 08:00:00 -33609

I'm confused. The 64-bit version of PERL should be producing the same
64-bit value as 'date(34, UCAL_JUNE, 4)' with TZ=GMT . The host is 
actually located in Dublin, Eire, where GMT is currently in effect .

$ ls -l /etc/localtime

lrwxrwxrwx. 1 root root 23 Jun 20 08:59 /etc/localtime -> /usr/share/zoneinfo/GMT


Version-Release number of selected component (if applicable):
4.2.1-9.1.el6_2

How reproducible:
100%

Steps to Reproduce:
See above. Use rpmbuild to rebuild the latest icu source RPM .

Actual results:
Build fails, in 'make -C source check' .

Expected results:
Build should succeed.

Additional info:
See above.