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Notes from my first attempt to work with PDL source

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
perl
Domain
build-system, documentation, testing

Research direction

Start by reproducing the reported commands from INSTALL, including perl -Iblib/lib -MPDL and make test TEST_FILES=t/core.t. Inspect Makefile, t/core.t, README, README.md, and the references to Known_problems; done means the source-build usage is documented, targeted testing behaves as expected, and the README references are clear.

Written by the indexing model from the issue text.

Description

Today I tried building PDL from source for the first time. I'm recording things I ran into; fixing them might help future newcomers.

I'm not sure if a Github issue is the best format, but arguably there are bugs...

What went well

PDL::FAQ pointed me to this GitHub project*, and the instructions in INSTALL worked: perl Makefile.PL, make, make test. (I didn't try make install or make doctest).

*I already knew about it, but I like it when the official docs are correct.

Problem/suggestion 1: document how to use it without installing

Summary: I needed to run perl with -Iblib/arch -Iblib/lib to use the PDL I just built with make.

The first thing I tried to do after make was perl -Iblib/lib -MPDL -E 'say $PDL::VERSION' because I was curious how the version number of git head is kept. This failed with:

PDL::Core object version 2.081 does not match bootstrap parameter 2.082 at /usr/libdata/perl5/amd64-openbsd/DynaLoader.pm line 223.
Compilation failed in require at (eval 1) line 4.
BEGIN failed--compilation aborted at (eval 1) line 4.
BEGIN failed--compilation aborted.

After some fiddling I got it working by passing -Iblib/arch in addition to -Iblib/lib.

Might be worth documenting this for those who don't want to make install for whatever reason.

Problem 2: make test TEST_FILES=t/core.t (or whatever) is slow and also doesn't work

According to the ExtUtils::MakeMaker docs, I should be able to run make test TEST_FILES=t/core.t to test just t/core.t.

First, it took a while for the command to run. I saw a lot of lines like Manifying 1 pod document. Manually commenting out the prerequisites for the pure_all target in Makefile sped it up significantly. Could the Makefile be fixed so that it realizes it already did whatever it's doing?

Second, it didn't actually work: I see

PERL_DL_NONLAZY=1 "/usr/bin/perl" "-MExtUtils::Command::MM" "-MTest::Harness" "-e" "undef *Test::Harness::Switches; test_harness(0, '../../blib/lib', '../../blib/arch')" t/core.t
Cannot detect source of 't/core.t'! at /usr/libdata/perl5/TAP/Parser/IteratorFactory.pm line 256.
        TAP::Parser::IteratorFactory::detect_source(TAP::Parser::IteratorFactory=HASH(0xd92ec844be0), TAP::Parser::Source=HASH(0xd93750ef0a0)) called at /usr/libdata/perl5/TAP/Parser/IteratorFactory.pm line 211
        TAP::Parser::IteratorFactory::make_iterator(TAP::Parser::IteratorFactory=HASH(0xd92ec844be0), TAP::Parser::Source=HASH(0xd93750ef0a0)) called at /usr/libdata/perl5/TAP/Parser.pm line 472
        TAP::Parser::_initialize(TAP::Parser=HASH(0xd93750d6fa0), HASH(0xd9380f50b20)) called at /usr/libdata/perl5/TAP/Object.pm line 55
        TAP::Object::new("TAP::Parser", HASH(0xd9380f50b20)) called at /usr/libdata/perl5/TAP/Object.pm line 130
        TAP::Object::_construct(TAP::Harness=HASH(0xd92dc373928), "TAP::Parser", HASH(0xd9380f50b20)) called at /usr/libdata/perl5/TAP/Harness.pm line 865
        TAP::Harness::make_parser(TAP::Harness=HASH(0xd92dc373928), TAP::Parser::Scheduler::Job=HASH(0xd93750f51a8)) called at /usr/libdata/perl5/TAP/Harness.pm line 664
        TAP::Harness::_aggregate_single(TAP::Harness=HASH(0xd92dc373928), TAP::Parser::Aggregator=HASH(0xd92c0976910), TAP::Parser::Scheduler=HASH(0xd93750f51f0)) called at /usr/libdata/perl5/TAP/Harness.pm line 756
        TAP::Harness::aggregate_tests(TAP::Harness=HASH(0xd92dc373928), TAP::Parser::Aggregator=HASH(0xd92c0976910), "t/core.t") called at /usr/libdata/perl5/Test/Harness.pm line 136
        Test::Harness::_aggregate_tests(TAP::Harness=HASH(0xd92dc373928), TAP::Parser::Aggregator=HASH(0xd92c0976910), "t/core.t") called at /usr/libdata/perl5/Test/Harness.pm line 118
        Test::Harness::_aggregate(TAP::Harness=HASH(0xd92dc373928), TAP::Parser::Aggregator=HASH(0xd92c0976910), "t/core.t") called at /usr/libdata/perl5/Test/Harness.pm line 151
        Test::Harness::runtests("t/core.t") called at /usr/libdata/perl5/ExtUtils/Command/MM.pm line 72
        ExtUtils::Command::MM::test_harness(0, "../../blib/lib", "../../blib/arch") called at -e line 1

The ../.. in the two paths passed to test_harness look suspicious there.

I was able to work around this by just running perl -MExtUtils::Command::MM -e 'test_harness(0,"blib/lib","blib/arch")' t/core.t

Problem 3: What is Known_problems? Two READMEs?

README and INSTALL refer to something called Known_problems. Is that a file that used to exist?

Also it's a little odd that both README and README.md exist. I guess the latter is there so the project looks nice on GitHub. Maybe README.md should explain that, and point to README for more information?

Dominant language
Perl
Stars
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Forks
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