Checking if your kit is complete...
Looks good
Writing Makefile for IOLayer::Base64
cp lib/IOLayer/Base64.pm blib/lib/IOLayer/Base64.pm
Manifying blib/man3/IOLayer::Base64.3
PERL_DL_NONLAZY=1 /Users/cpanrun/build/5.10.0/bin/perl "-MExtUtils::Command::MM" "-e" "test_harness(1, 'blib/lib', 'blib/arch')" t/*.t
t/01basic....1..22
ok 1 - use IOLayer::Base64;
"my" variable $out masks earlier declaration in same scope at t/01basic.t line 67.
"my" variable $in masks earlier declaration in same scope at t/01basic.t line 86.
ok 2 - check eol setting first time
Unknown PerlIO layer "Via" at t/01basic.t line 33.

#   Failed test 'opening 't/test.mime' for writing'
#   at t/01basic.t line 33.
print() on closed filehandle $out at t/01basic.t line 38.
not ok 3 - opening 't/test.mime' for writing

#   Failed test 'print to file'
#   at t/01basic.t line 38.
not ok 4 - print to file

#   Failed test 'closing encoding handle'
not ok 5 - closing encoding handle
#   at t/01basic.t line 39.

#   Failed test 'opening without layer'
not ok 6 - opening without layer
#   at t/01basic.t line 45.
readline() on closed filehandle $test at t/01basic.t line 46.

#   Failed test 'check encoded content'
not ok 7 - check encoded content
#   at t/01basic.t line 46.
#          got: undef
#     expected: 'VGhpcyBpcyBhIHTpc3QgZm9yIE1JTUUtZW5jb2RlZCAoYmFzZTY0KSB0ZXh0IHRoYXQgaGFzIGjg
# cmRseSBhbnkgc3Bl52lhbCBjaGFyYWN0ZXJzIGluIGl0IGJ1dCB3aGljaCBpcyBub25ldGhlbGVz
# cyBhbiBpbmRpY2F0aW9uIG9mIHRoZSByZWFsIHdvcmxkLgoKV2l0aCBsb25nIGxpbmVzIGFuZCBw
# YXJhZ3JhcGhzIGFuZCBhbGwgdGhhdCBzb3J0IG9mIHRoaW5ncy4KCkFuZCBzbyBvbiBhbmQgc28g
# b24uCi0tIApBbmQgYSBzaWduYXR1cmUK
# '

#   Failed test 'close test handle'
not ok 8 - close test handle
#   at t/01basic.t line 47.
Unknown PerlIO layer "Via" at t/01basic.t line 53.

#   Failed test 'opening 't/test.mime' for reading'
#   at t/01basic.t line 53.
readline() on closed filehandle $in at t/01basic.t line 56.
not ok 9 - opening 't/test.mime' for reading

#   Failed test 'check decoding'
not ok 10 - check decoding
#   at t/01basic.t line 56.
#          got: ''
#     expected: 'This is a tést for MIME-encoded (base64) text that has hàrdly any speçial characters in it but which is nonetheless an indication of the real world.
# 
# With long lines and paragraphs and all that sort of things.
# 
# And so on and so on.
# -- 
# And a signature
# '

#   Failed test 'close decoding handle'
#   at t/01basic.t line 57.
not ok 11 - close decoding handle
Unknown PerlIO layer "Via" at t/01basic.t line 66.
ok 12 - check eol setting second time

#   Failed test 'opening 't/test.mime' for writing without eol'
#   at t/01basic.t line 66.
not ok 13 - opening 't/test.mime' for writing without eol
print() on closed filehandle $out at t/01basic.t line 71.

#   Failed test 'print to file without eol'
#   at t/01basic.t line 71.
not ok 14 - print to file without eol

#   Failed test 'closing encoding handle without eol'
#   at t/01basic.t line 72.
not ok 15 - closing encoding handle without eol

#   Failed test 'opening without layer without eol'
#   at t/01basic.t line 78.
readline() on closed filehandle $test at t/01basic.t line 79.
not ok 16 - opening without layer without eol

#   Failed test 'check encoded content without eol'
#   at t/01basic.t line 79.
not ok 17 - check encoded content without eol
#          got: undef
#     expected: 'VGhpcyBpcyBhIHTpc3QgZm9yIE1JTUUtZW5jb2RlZCAoYmFzZTY0KSB0ZXh0IHRoYXQgaGFzIGjgcmRseSBhbnkgc3Bl52lhbCBjaGFyYWN0ZXJzIGluIGl0IGJ1dCB3aGljaCBpcyBub25ldGhlbGVzcyBhbiBpbmRpY2F0aW9uIG9mIHRoZSByZWFsIHdvcmxkLgoKV2l0aCBsb25nIGxpbmVzIGFuZCBwYXJhZ3JhcGhzIGFuZCBhbGwgdGhhdCBzb3J0IG9mIHRoaW5ncy4KCkFuZCBzbyBvbiBhbmQgc28gb24uCi0tIApBbmQgYSBzaWduYXR1cmUK'

#   Failed test 'close test handle without eol'
not ok 18 - close test handle without eol
#   at t/01basic.t line 80.
Unknown PerlIO layer "Via" at t/01basic.t line 86.

#   Failed test 'opening 't/test.mime' for reading without eol'
not ok 19 - opening 't/test.mime' for reading without eol
#   at t/01basic.t line 86.
readline() on closed filehandle $in at t/01basic.t line 89.

#   Failed test 'check decoding without eol'
not ok 20 - check decoding without eol
#   at t/01basic.t line 89.
#          got: ''
#     expected: 'This is a tést for MIME-encoded (base64) text that has hàrdly any speçial characters in it but which is nonetheless an indication of the real world.
# 
# With long lines and paragraphs and all that sort of things.
# 
# And so on and so on.
# -- 
# And a signature
# '

#   Failed test 'close decoding handle without eol'
not ok 21 - close decoding handle without eol
#   at t/01basic.t line 90.

#   Failed test 'remove test file 't/test.mime''
not ok 22 - remove test file 't/test.mime'
#   at t/01basic.t line 94.
# Looks like you failed 19 tests of 22.
dubious
	Test returned status 19 (wstat 4864, 0x1300)
DIED. FAILED tests 3-11, 13-22
	Failed 19/22 tests, 13.64% okay
Failed Test Stat Wstat Total Fail  List of Failed
-------------------------------------------------------------------------------
t/01basic.t   19  4864    22   19  3-11 13-22
Failed 1/1 test scripts. 19/22 subtests failed.
Files=1, Tests=22,  0 wallclock secs ( 0.07 cusr +  0.03 csys =  0.10 CPU)
Failed 1/1 test programs. 19/22 subtests failed.
make: *** [test_dynamic] Error 19