Add xtb program package

[awvwgk]

This is a Fortran project supporting both cmake and meson as build system. The main production builds are usually performed with Intel Fortran and MKL backend using the meson build. GCC support was only added.

Checklist

• Title of this PR is meaningful: e.g. "Adding my_nifty_package", not "updated meta.yaml"
• License file is packaged (see here for an example)
• Source is from official source
• Package does not vendor other packages. (If a package uses the source of another package, they should be separate packages or the licenses of all packages need to be packaged)
• If static libraries are linked in, the license of the static library is packaged.
• Build number is 0
• A tarball (url) rather than a repo (e.g. git_url) is used in your recipe (see here for more details)
• GitHub users listed in the maintainer section have posted a comment confirming they are willing to be listed there

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipes/xtb) and found some lint.

Here's what I've got...

For recipes/xtb:

• Selectors are suggested to take a <two spaces>#<one space>[<expression>] form. See lines [19]
• Non noarch: python packages should have a python requirement without any version constraints.
• Non noarch: python packages should have a python requirement without any version constraints.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipes/xtb) and found some lint.

Here's what I've got...

For recipes/xtb:

• Non noarch: python packages should have a python requirement without any version constraints.
• Non noarch: python packages should have a python requirement without any version constraints.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/xtb) and found it was in an excellent condition.

[awvwgk]

@conda-forge/staged-recipes Interestingly the build fails for Linux but not for Mac. The Mac build was performed with the trick from @chrisburr introduced in #10569 (comment).

The error from the pipeline is not really helpful:

ERROR :: get_rpaths_raw()=[] and patchelf=[''] disagree for /home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho/bin/xtb :: 
ERROR :: get_rpaths_raw()=[] and patchelf=[''] disagree for /home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho/lib/libxtb.so.6.2.2 :: 
WARNING: Disagreement in get_linkages(filename=/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho/bin/xtb, resolve_filenames=True, recurse=False, sysroot=/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_build_env/x86_64-conda_cos6-linux-gnu/sysroot/, envroot=/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho, arch=native):
 lief: {'/', '$RPATH/;'}
pyldd: {'/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho/bin/../lib/libblas.so.3', '/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_build_env/x86_64-conda_cos6-linux-gnu/sysroot/lib/libm.so.6', '/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_build_env/x86_64-conda_cos6-linux-gnu/sysroot/lib/libc.so.6', '/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho/bin/../lib/libgomp.so.1', '/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_build_env/x86_64-conda_cos6-linux-gnu/sysroot/lib/libpthread.so.0', '/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho/bin/../lib/liblapack.so.3', '/home/conda/staged-recipes/build_artifacts/xtb_1579645352273/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeho/bin/../lib/libgfortran.so.4'}
  (using lief)
  ERROR :: $RPATH/; not in prefix_owners
  ERROR (xtb,bin/xtb): / not found in sysroot, is this binary repackaging? .. do you need to use install_name_tool/patchelf?
  ERROR (xtb,bin/xtb): $RPATH/; not found in sysroot, is this binary repackaging? .. do you need to use install_name_tool/patchelf?
   INFO (xtb,lib/libxtb.so.6.2.2): Needed DSO x86_64-conda_cos6-linux-gnu/sysroot/lib/libm.so.6 found in CDT/compiler package conda-forge::gcc_impl_linux-64-7.3.0-hd420e75_4
   INFO (xtb,lib/libxtb.so.6.2.2): Needed DSO lib/libgfortran.so.4 found in conda-forge::libgfortran-ng-7.3.0-hdf63c60_4
   INFO (xtb,lib/libxtb.so.6.2.2): Needed DSO lib/liblapack.so.3 found in conda-forge::liblapack-3.8.0-7_h6e990d7_netlib
   INFO (xtb,lib/libxtb.so.6.2.2): Needed DSO x86_64-conda_cos6-linux-gnu/sysroot/lib/libc.so.6 found in CDT/compiler package conda-forge::gcc_impl_linux-64-7.3.0-hd420e75_4
Traceback (most recent call last):
  File "/home/conda/.ci_support/build_all.py", line 135, in <module>
    build_all(args.recipes_dir, args.arch)
  File "/home/conda/.ci_support/build_all.py", line 68, in build_all
    build_folders(recipes_dir, new_comp_folders, arch, channel_urls)
  File "/home/conda/.ci_support/build_all.py", line 125, in build_folders
    conda_build.api.build([recipe], config=get_config(arch, channel_urls))
  File "/opt/conda/lib/python3.7/site-packages/conda_build/api.py", line 209, in build
    notest=notest, need_source_download=need_source_download, variants=variants)
  File "/opt/conda/lib/python3.7/site-packages/conda_build/build.py", line 2344, in build_tree
    notest=notest,
  File "/opt/conda/lib/python3.7/site-packages/conda_build/build.py", line 1643, in build
    newly_built_packages = bundlers[pkg_type](output_d, m, env, stats)
  File "/opt/conda/lib/python3.7/site-packages/conda_build/build.py", line 1002, in bundle_conda
    files = post_process_files(metadata, initial_files)
  File "/opt/conda/lib/python3.7/site-packages/conda_build/build.py", line 867, in post_process_files
    post_build(m, new_files, build_python=python)
  File "/opt/conda/lib/python3.7/site-packages/conda_build/post.py", line 1150, in post_build
    check_overlinking(m, files)
  File "/opt/conda/lib/python3.7/site-packages/conda_build/post.py", line 1087, in check_overlinking
    m.config.enable_static)
  File "/opt/conda/lib/python3.7/site-packages/conda_build/post.py", line 1051, in check_overlinking_impl
    raise OverLinkingError(overlinking_errors)
conda_build.exceptions.OverLinkingError: overlinking check failed 
['  ERROR (xtb,bin/xtb): / not found in sysroot, is this binary repackaging? .. do you need to use install_name_tool/patchelf?', '  ERROR (xtb,bin/xtb): $RPATH/; not found in sysroot, is this binary repackaging? .. do you need to use install_name_tool/patchelf?']

Any idea? I found conda/conda-build#3588 mentioning the first two error lines.