cpan> install SVG::TT::Graph::XY

 LLAP/SVG-TT-Graph-1.02.tar.gz
  C:\STRAWB~1\c\bin\gmake.exe -- OK
Running make test for LLAP/SVG-TT-Graph-1.02.tar.gz
"C:\Strawberry\perl\bin\perl.exe" "-MExtUtils::Command::MM" "-MTest::H
+arness" "-e" "undef *Test::Harness::Switches; test_harness(0, 'blib\l
+ib', 'blib\arch')" t/*.t
t/01_main.t ............ ok
t/02_basic.t ........... 1/85 POSIX::tzset not implemented on this arc
+hitecture at blib/lib/SVG/TT/Graph/TimeSeries.pm line 582, <DATA> lin
+e 593.
# Looks like your test exited with 255 just after 72.
t/02_basic.t ........... Dubious, test returned 255 (wstat 65280, 0xff
+00)
Failed 13/85 subtests
t/03_methods.t ......... ok
t/author-no-tabs.t ..... skipped: these tests are for testing by the a
+uthor
t/author-pod-syntax.t .. skipped: these tests are for testing by the a
+uthor

Test Summary Report
-------------------
t/02_basic.t         (Wstat: 65280 Tests: 72 Failed: 0)
  Non-zero exit status: 255
  Parse errors: Bad plan.  You planned 85 tests but ran 72.
Files=5, Tests=178,  1 wallclock secs ( 0.00 usr +  0.01 sys =  0.01 C
+PU)
Result: FAIL
Failed 1/5 test programs. 0/178 subtests failed.
gmake: *** [Makefile:884: test_dynamic] Error 255
Lockfile removed.
  LLAP/SVG-TT-Graph-1.02.tar.gz
  C:\STRAWB~1\c\bin\gmake.exe test -- NOT OK
//hint// to see the cpan-testers results for installing this module, t
+ry:
  reports LLAP/SVG-TT-Graph-1.02.tar.gz
Stopping: 'install' failed for 'SVG::TT::Graph::XY'.
Failed during this command:
 LLAP/SVG-TT-Graph-1.02.tar.gz                : make_test NO
[download]

Looks like you guessed it:

t/02_basic.t ........... 1/85 POSIX::tzset not implemented on this arc
+hitecture at blib/lib/SVG/TT/Graph/TimeSeries.pm line 582, <DATA> lin
+e 593.
# Looks like your test exited with 255 just after 72.
t/02_basic.t ........... Dubious, test returned 255 (wstat 65280, 0xff
+00)
[download]

More info: rt://131606, https://github.com/ranguard/svg-tt-graph/pull/31.

I can think of a work around to patch the module to support Windows, but won't have access to a Windows machine until the weekend. I've made a note to dig deeper I to the Strawberry build/tzset issue.

Got some info from the Strawberry folks {not the developers about fixing it, but someone else at cpan mentioning the problem}:

"tzset" is common Perl command which our MIDAS scheduling software utilizes when calculating times and time zones.

...

We understand that from around June 2010, tzset is no longer recognized or implemented in Strawberry Perl. We have no idea why this is the case, as there is very little information available from the developers of Strawberry Perl. It is unknown whether this is just a bug/glitch in Strawberry Perl, or if this common functionality has been permanently and intentionally removed.

I'm guessing that, since it is now a decade later and no tzset, that it has been permanently removed. I wonder if there's a workaround? tzset seems simple enough:

"tzset" This is identical to the C function "tzset()" for setting the current timezone based on the environment variable "TZ", to be used by "ctime()", "localtime()", "mktime()", and "strftime()" functions.

But what's amusing {perhaps} I can't find a man page for the C tzset() function on my system {Ubuntu 18.04.3}

Over on stackexchange there is a post on this very topic at tzset

That post asks

Notice how on my system, the hour changes without calling tzset. This holds true on recent versions of Perl in Ubuntu and Illumos, as well as Perl v5.8.8 on Solaris 10.

So if all my tests indicate that tzset has no effect, why / what other systems require tzset to be called explicitly? Do I still need to call tzset to remain compatible with certain environments, or is it now a thing of the past?

and one of the replies says

TL;DR: Starting with Perl v5.8.9 (released in 2011) calling tzset when changing $ENV{TZ} isn't needed anymore.

That seems to mean I could go into the code for SVG::TT::Graph and just edit out the call to tzset?

I can download the module from CPAN and I guess i'll find out if it is as easy as perl Makefile.PL in the downloaded module directory.. but.. then on Unix I'd do something like "make", "make test" and "make install". I guess I'll find out if the gmake is up to the job.