Update here. I am a new comer to Perl, and it takes one day to investigate this issue. I have not fixed it, while I find some useful info.

[root@sparts Unicode-Map8-0.13-kCcefS]# pwd
/root/.cpan/build/Unicode-Map8-0.13-kCcefS
[root@sparts Unicode-Map8-0.13-kCcefS]# make clean
[root@sparts Unicode-Map8-0.13-kCcefS]# make
...
map8x.c: In function ‘map8_recode8’:
map8x.c:321: warning: pointer targets in passing argument 1 of ‘strlen
+’ differ in signedness
map8x.c:314: warning: unused variable ‘uc’
...
[root@sparts Unicode-Map8-0.13-kCcefS]# make test
PERL_DL_NONLAZY=1 /usr/bin/perl "-MExtUtils::Command::MM" "-e" "test_h
+arness(0, 'blib/lib', 'blib/arch')" t/*.t
t/callback.t .. ok   
t/map8.t ........ No subtests run 
t/compat.t .... ok   
t/unistr.t .... ok
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I use "make testdb TEST_FILE=t/map8.t", when excuting the below line:

print "not " unless $no->recode8($l1, "xyz{|}") eq "xyzæøå";
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I see " DB<2> x $! 0 'Bad file descriptor'", so I guess it seems caused by recode8(). I commented all recode() and modify the test count in map8.t, and then run "make test" again, it is "PASSED". In order to look more deeply, I created the simply test file including recode8:(named cm.t)

print "1..1\n";

use strict;
use Unicode::Map8 qw(NOCHAR);

print "MAPS_DIR = $Unicode::Map8::MAPS_DIR\n";

my $l1 = Unicode::Map8->new("latin1") || die;
my $no = Unicode::Map8->new("no")     || die;

#print "not " unless $no->recode8($l1, "xyz{|}") eq "xyzæøå";

my $t1 = $no->recode8($l1, "xyz{|}");

print "ok 1\n";
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make test again

[root@sparts Unicode-Map8-0.13-kCcefS]# make test
PERL_DL_NONLAZY=1 /usr/bin/perl "-MExtUtils::Command::MM" "-e" "test_h
+arness(0, 'blib/lib', 'blib/arch')" t/*.t
t/callback.t .. ok   
t/cm.t ........ Usage: Unicode::Map8::recode8(m1, m2, str) at t/cm.t l
+ine 15.
t/cm.t ........ Dubious, test returned 9 (wstat 2304, 0x900)
Failed 1/1 subtests 
t/compat.t .... ok   
t/unistr.t .... ok   

Test Summary Report
-------------------
t/cm.t      (Wstat: 2304 Tests: 0 Failed: 0)
  Non-zero exit status: 9
  Parse errors: Bad plan.  You planned 1 tests but ran 0.
Files=5, Tests=20,  0 wallclock secs ( 0.05 usr  0.04 sys +  0.14 cusr
+  0.06 csys =  0.29 CPU)
Result: FAIL
Failed 1/5 test programs. 0/20 subtests failed.
make: *** [test_dynamic] Error 255
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I also see recode8() is defined in Map8.xs

recode8(m1, m2, str)
        Map8* m1
        Map8* m2
        PREINIT:
            STRLEN len;
            STRLEN rlen;
            char*  res;
        INPUT:
            char* str = SvPV(ST(2), len);
        CODE:
            RETVAL = newSV(len + 1);
            SvPOK_on(RETVAL);
            res = SvPVX(RETVAL);
            map8_recode8(m1, m2, str, res, len, &rlen);
            res[rlen] = '\0';
            SvCUR_set(RETVAL, rlen);
        OUTPUT:
            RETVAL
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It needs 3 parameters:($m1,$m2,str), and I try to modify the cm.t as "my $t1 = $no->recode8($no, $l1, "xyz{|}");" and then "make test" also show the same error. Here, I do not know how to do it next, can you pls give any hint? Thanks, Phillip