Remove usage of deprecated std.xml

[andre2007]

In this case, parsing the xml with std.regex seems to make most sense.
Example XML

<metadata modelVersion="1.1.0">
  <groupId>dubpackages</groupId>
  <artifactId>maven-dubpackage</artifactId>
  <versioning>
    <latest>1.0.6</latest>
    <release>1.0.6</release>
    <versions>
      <version>1.0.5</version>
      <version>1.0.6</version>
    </versions>
    <lastUpdated>20180317184845</lastUpdated>
  </versioning>
</metadata>

[dlang-bot]

Thanks for your pull request and interest in making D better, @andre2007! We are looking forward to reviewing it, and you should be hearing from a maintainer soon.
Please verify that your PR follows this checklist:

• My PR is fully covered with tests (you can see the coverage diff by visiting the details link of the codecov check)
• My PR is as minimal as possible (smaller, focused PRs are easier to review than big ones)
• I have provided a detailed rationale explaining my changes
• New or modified functions have Ddoc comments (with Params: and Returns:)

Please see CONTRIBUTING.md for more information.

---

If you have addressed all reviews or aren't sure how to proceed, don't hesitate to ping us with a simple comment.

[WebFreak001]

I just noticed one other thing: before it would only search for <version>...</version> inside a <versions>...</versions> block. Can it happen that in maven there is anywhere else a <version> than in a <versions> block? Like some metadata version or something.

[andre2007]

You are right, I have to extend the regex to find version tags only within a versions parent tag. (Just saw an example where version tag is after artifactId).

[WebFreak001]

I'm really not quite sold on the conversion to regex and manual string operations. XML could contain a lot more weird stuff like whitespace in the tags, random attributes, the tags being in a completely different nesting level (like in some sub-tags instead of the expected root tag) than expected, etc.

How big would putting the entire undeaD xml package in be?

[andre2007]

3100 lines or 90kb. Should I add it?

[WebFreak001]

hm I don't think I should decide on that, what does @wilzbach think?

[andre2007]

@wilzbach should I add the whole undead.xml file, what do you think?

[rikkimax]

Alternatively do what DCD and friends do. Git submodule for script (i.e. makefile) and dub dependency for dub.

[wilzbach]

@wilzbach should I add the whole undead.xml file, what do you think?

Hmm, I unfortunately don't see a better alternative as well. This really looks like the easiest solution to this problem as long as we don't trust dub enough to bootstrap itself or want to maintain easy bootstrapping of dub on new platforms.

Though we should add a big comment on the header stating that it's dead code, link to the undead package and maybe even put it in under an undead folder as well?

Re git submodules: I don't think it matters much whether it's a git submodule or just a copy/paste as I don't expect this file to change. The git submodule will require small adaptions to the CIs, build script and dub distro packages, but that's marginal as long as it's mentioned in a changelog entry.

If no one else has a strong opinion, I would leave the final choice on copy/paste or git submodule to you. I'm fine either way.

[andre2007]

As the other dependencies are also code copies and in the long run we will have a better solution, when dub bootstrapping is available, I favour copying the file into it.
I will change the pr.

[andre2007]

macOS-10.15 LDC master fails due to an unrelated Vibe-d SSL linker issue:

d_tls.a(vibe.stream.openssl.o)
"_get_rfc3526_prime_2048", referenced from:
__D4vibe6stream7openssl14OpenSSLContext11setDHParamsMFNeAyaZv in libvibe-d_tls.a(vibe.stream.openssl.o)
"_sk_num", referenced from:
__D6deimos7openssl9safestack__T10SKM_sk_numTSQBqQBm6x509v315GENERAL_NAME_stZ__TQBwZQCaFNbPSQDkQDgQDb__T8STACK_OFTQCrZQoZi in libvibe-d_tls.a(vibe.stream.openssl.o)
(maybe you meant: __D6deimos7openssl9safestack__T10SKM_sk_numTSQBqQBm6x509v315GENERAL_NAME_stZ__TQBwZQCaFNbPSQDkQDgQDb__T8STACK_OFTQCrZQoZi)
"_sk_value", referenced from:
__D6deimos7openssl9safestack__T12SKM_sk_valueTSQBsQBo6x509v315GENERAL_NAME_stZ__TQByZQCcFNbPSQDmQDiQDd__T8STACK_OFTQCrZQoiZPQDa in libvibe-d_tls.a(vibe.stream.openssl.o)
(maybe you meant: __D6deimos7openssl9safestack__T12SKM_sk_valueTSQBsQBo6x509v315GENERAL_NAME_stZ__TQByZQCcFNbPSQDmQDiQDd__T8STACK_OFTQCrZQoiZPQDa)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Error: /usr/bin/cc failed with status: 1
ldc2 failed with exit code 1.
[ERROR] /Users/runner/work/dub/dub/test/ddox.sh:11 command failed
[ERROR] Script failure.

[andre2007]

Ping :)