The least you could do after ripping someone is to offer the answer. I've actually hit a similar problem:
Note, USERID, and SID are I believe set correctly

# env ORACLE_SID=oraclesid ORACLE_USERID=user/pass ORACLE_HOME=/u01/app/oracle/product/816/ make test
PERL_DL_NONLAZY=1 /usr/bin/perl -Iblib/arch -Iblib/lib -I/usr/perl5/5.00503/i86pc-solaris -I/usr/perl5/5.00503 -e 'use Test::Harness qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t
t/base..............FAILED tests 4-5
Failed 2/5 tests, 60.00% okay
t/general...........install_driver(Oracle) failed: Can't load 'blib/arch/auto/DBD/Oracle/Oracle.so' for module DBD::Oracle: ld.so.1: /usr/bin/perl: fatal: libclntsh.so.8.0: open failed: No such file or directory at /usr/perl5/5.00503/i86pc-solaris/DynaLoader.pm line 169.

at (eval 1) line 3
Perhaps a required shared library or dll isn't installed where expected
at t/general.t line 20
dubious
Test returned status 255 (wstat 65280, 0xff00)
t/long..............Can't load 'blib/arch/auto/DBD/Oracle/Oracle.so' for module DBD::Oracle: ld.so.1: /usr/bin/perl: fatal: libclntsh.so.8.0: open failed: No such file or directory at /usr/perl5/5.00503/i86pc-solaris/DynaLoader.pm line 169.
at t/long.t line 4
BEGIN failed--compilation aborted at t/long.t line 4.
dubious
Test returned status 255 (wstat 65280, 0xff00)
t/plsql.............Can't load 'blib/arch/auto/DBD/Oracle/Oracle.so' for module DBD::Oracle: ld.so.1: /usr/bin/perl: fatal: libclntsh.so.8.0: open failed: No such file or directory at /usr/perl5/5.00503/i86pc-solaris/DynaLoader.pm line 169.
at t/plsql.t line 17
BEGIN failed--compilation aborted at t/plsql.t line 17.
dubious
Test returned status 255 (wstat 65280, 0xff00)
t/reauth............skipping test on this platform
Failed Test Status Wstat Total Fail Failed List of failed -------------------------------------------------------------------------------
t/base.t 5 2 40.00% 4-5
t/general.t 255 65280 ?? ?? % ??
t/long.t 255 65280 ?? ?? % ??
t/plsql.t 255 65280 ?? ?? % ??
1 test skipped.
Failed 4/5 test scripts, 20.00% okay. 2/5 subtests failed, 60.00% okay.
*** Error code 29
make: Fatal error: Command failed for target `test_dynamic'

ldd -s blib/arch/auto/DBD/Oracle/Oracle.so

you'll probably find that its looking in /usr/lib for libclntsh.so.8.0 and since its probably in $ORACLE_HOME/lib you're getting that error.