环境：AIX 6.1 + Oracle 10.2.0.4
现象：在做xtts测试时，源环境使用Oracle自带的perl执行xttdriver.pl报错如下：

$ $ORACLE_HOME/perl/bin/perl xttdriver.pl
Can't locate Getopt/Long.pm in @INC (@INC contains: /project/aix5l64/main/APACHE/perl/bin/AIX/Opt/lib/5.8.3/aix-thread-multi /project/aix5l64/main/APACHE/perl/bin/AIX/Opt/lib/5.8.3 /project/aix5l64/main/APACHE/perl/bin/AIX/Opt/lib/site_perl/5.8.3/aix-thread-multi /project/aix5l64/main/APACHE/perl/bin/AIX/Opt/lib/site_perl/5.8.3 /project/aix5l64/main/APACHE/perl/bin/AIX/Opt/lib/site_perl .) at xttdriver.pl line 126.
BEGIN failed--compilation aborted at xttdriver.pl line 126.

而在目标环境Linux6.8 + Oracle 11.2.0.4 就正常，起初我没多想这个问题，以为是10g的自带perl版本过低不支持，第一轮测试使用了系统自带perl可执行。
但在后续测试中发现系统自带的perl在执行过程中也是有很多类似错误，虽然最终完成，但担心有其他隐患，和有经验的同事进一步沟通，得知之前成功的xtts项目都是采用oracle自带的perl，某些版本报这个错误是需要额外设置环境变量。

具体依据下面的MOS文档，需要设置PER5LIB环境变量：

• perl xttdriver.pl fails: Can't locate Getopt/Long.pm in @INC (文档 ID 1912400.1)

临时设置PERL5LIB环境变量：

$ export PERL5LIB=$ORACLE_HOME/perl/lib

再次使用Oracle自带的perl执行xttdriver.pl不再报之前的错误，这里测试没加参数，就正常列出了xttdriver.pl的使用方法：

$ $ORACLE_HOME/perl/bin/perl xttdriver.pl
============================================================
trace file is /tmp/Nov15_Thu_16_29_45_413//Nov15_Thu_16_29_45_413_.log
=============================================================

--------------------------------------------------------------------
Parsing properties
--------------------------------------------------------------------


--------------------------------------------------------------------
Done parsing properties
--------------------------------------------------------------------


--------------------------------------------------------------------
Checking properties
--------------------------------------------------------------------


--------------------------------------------------------------------
Done checking properties
--------------------------------------------------------------------


   This program prepares, backsup and rollsforward tablespaces
   for cross-platform transportable tablespaces.

    usage: xttdriver.pl
                  {[--backup|-b] || [--bkpincr|-B] || [--bkpexport/E]
                   [--resincrdmp|M]
                   [--fixnewdf|W]
                   [--convert/-c] || [--generate|-e] || [--incremental|-i] ||
                   [[--prepare|-p] || [--getfile|-G]] ||
                   [--restore|R] || [--recover|X]
                   [--rollforward|-r [--rolltbs|-T <TBS1[,TBS2]>] ||
                   [--determinescn|-s] ||
                   [--orasid/O] || [--orahome|-o]]
                   [--help|-h]}

       Additional options
       ------------------
               [--debug|d] [--clearerrorfile|-C] [--xttdir|Dir <tmpdir>]
               [-F/--propfile] [-I/--propdir]

     -b  : For 12c and above, generate transportable backups
     -B  : For 12c and above, generate level 1 transportable backups
     -c  : conversion of datafiles
     -M  : create the dump file from the generated backup
     -e  : generate impdp script: export over new link
     -i  : incremental backup
     -p  : prepare
     -G  : get datafiles from source database using get_file, should not
           be used together with -p
     -r  : roll forward datafiles
     -s  : new from_scn values into xttplan.txt
     -R  : For 12c restore the datafiles from the backups
     -X  : For 12c recover the datafiles from the backups
     -T  : roll forward specific tablespace(s)
     -h  : this (help) message (Default)
     -d  : provides more debug information, also rman is called with debug
           option so that tracing is better.
     -L  : delete the ERROR FILE and proceed with the execution
     -D  : Instead of defining environement variable, user can pass tmpdir
           through xttdir
     -O  : Use this option to pass ORACLE_SID to override the environment
           variable
     -o  : Use this option to pass ORACLE_HOME to override the environment
           variable
     -I  : Use this option to mention the location from where the script
           will pick the properties file etc
     -F  : Use this option to mention the location from where the script
           will pick the properties file.
     -W  : Will try to reconstruct files on the destination after new 
           datafiles have been added

    example: xttdriver.pl -p
             xttdriver.pl -i
             xttdriver.pl -r
             xttdriver.pl -s

$ 

既然如此，后续还是建议使用oracle自带的perl进行测试。
2018-11-18修正说明：最终发现这个不算是问题，因为实际上源端我使用系统自带的perl也并没有任何报错，实际报错是目标端perl在进行增量恢复时有报错，具体是"Can't locate strict.pm in @INC..."，虽然看起来和上文很像，但模块名称有区别，而从MOS文档Migrate database to Exadata with DBMS_FILE_TRANSFER (文档 ID 1902618.1)中可以看到这个错误实际是可以忽略的，原话是：
It is safe to ignore the "Can't locate strict.pm in @INC..." messages. We believe those are the result of the Perl pragma 'use strict' in the asmcmdcore.