Co-authored-by: Veselin Dobrev <dobrev1@llnl.gov>

This commit adds output to the "spack external find"
command to inform users of the result of the operation.

It also fixes a bug introduced in #17804 due to the fact
that a function was not updated to conform to the new
packages.yaml format (_get_predefined_externals).

* Update the change to add gomp compatibity to llvm-openmp.

* Update the change to add gomp compatibity to llvm-openmp using append instead of extend.

* Fix flake8 issue.

Co-authored-by: Jim Galarowicz <jgalarowicz@newmexicoconsortium.org>

* pFUnit: Added support for version 4

pFUnit v4 uses submodules, so we must fetch from the repo rather
than grabbing the tarball (see #11642).

* pFUnit: Added conflicts

pFUnit 4 causes an internal compiler error with gcc 7.2.0, and
several pFUnit versions are incompatible with shared libraries.

* pFUnit: Added conflicts for version 4

Verson 4 uses Fortran 2008 features and cannot be built with gcc
compilers prior to 8.4.

* pFUnit: Fixed conflicts/dependencies as suggested

* pFUnit: Version 4 no longer fetches from git

Checksummable files are fetched instead.

* pFUnit: Simplify major version check

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

* pFUnit: Removed unnecessary patch for v4

The patch is still applied to v3.

* pFUnit: Modified MPI flag for v4

pFUnit v3 and v4 use different CMake flags to enable/disable MPI
support. Also added a conflict for v3 with MPI enabled using
gfortran 10, since newer gfortran is more finicky about datatypes.

* pFUnit: Rearranged mpi logic

* pFUnit: changed m4 to a build dependency

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

* pFUnit: Added URL back

I did not realize it was needed by "spack versions" and
"spack checksum". Thanks @adamjstewart!

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

* ROCm Mathlibs

* fixed the review comments

* fixed flake8 issues

* Don't detect Apple's clang as gcc@4.2.1
* Avoid inspecting links except for Cray platforms
* Always return string paths from compiler properties
* Improved name-based filtering (apt-based packages)

* IOR package: added 3.3.0rc1 and develop version

* IOR package: reordered versions, set 3.2.1 as preferred

When the user explicitly sets ~fortran, mpich builds without fortran
support. This will make building C/C++ libraries using clang easier,
since clang does not offer a fortran compiler by default (yet).

Since the user has to disable Fortran support explicitly, this change
is not breaking.

* Handle uninstalled rootspecs in buildcache

- Do not parse specs / find matching specs when in an environment and no
package string is provided
- Error only when a spec.yaml or spec string are not installed. In an
environment it is fine when the root spec does not exist.
- When iterating through the matched specs, simply skip uninstalled
packages

fixes #18031

With this fix "spack config update" can update YAML
files that contain comments, while previously it
couldn't.

* llvm: added external detection capabilities

* Added comment with reference to external package detection docs

* Fix typo in a comment

* Run Python2.6 unit tests on Github Actions
* Skip url tests on Python 2.6 to reduce waiting times
* Skip foreground background tests on Python 2.6 to reduce waiting times
* Removed references to Travis in the documentation
* Deleted install_patchelf.sh (can be installed from repo on CentOS 6)

* Buildcache:
   * Try mocking an install of quux, corge and garply using prebuilt binaries
   * Put patchelf install after ccache restore
   * Add script to install patchelf from source so it can be used on Ubuntu:Trusty which does not have a patchelf pat package. The script will skip building on macOS
   * Remove mirror at end of bindist test
   * Add patchelf to Ubuntu build env
   * Revert mock patchelf package to allow other tests to run.
   * Remove depends_on('patchelf', type='build') relying instead on
   * Test fixture to ensure patchelf is available.

* Call g++ command to build libraries directly during test build

* Flake8

* Install patchelf in before_install stage using apt unless on Trusty where a build is done.

* Add some symbolic links between packages

* Flake8

* Flake8:

* Update mock packages to write their own source files

* Create the stage because spec search does not create it any longer

* updates after change of list command arguments

* cleanup after merge

* flake8

Updated actions where needed

Style and documentation tests take just a few minutes
to run. Since in Github actions one can't restart a single
job but needs to restart an entire workflow, here we group
tests with similar duration together.

- [x] Remove references to `master` branch
- [x] Document how release branches are structured
- [x] Document how to make a major release
- [x] Document how to make a point release
- [x] Document how to do work in our release projects

- [x] remove master from github actions
- [x] remove master from .travis.yml
- [x] make `develop` the default branch for `spack ci`

* Move flake8 tests on Github Actions

* Move shell test to Github Actions

* Moved documentation build to Github Action

* Don't run coverage on Python 2.6

Since we get connection errors consistently on Travis
when trying to upload coverage results for Python 2.6,
avoid computing coverage entirely to speed-up tests.

This is needed because libcuda is used by the driver,
whereas libcudart is used by the runtime. CMake searches
for cudart instead of cuda.

On LLNL LC systems, libcuda is only found in compat and
stubs directories, meaning that the lookup of libraries
fails.

`spack -V` stopped working when we added the `releases/latest` tag to
track the most recent release. It started just reporting the version,
even on a `develop` checkout. We need to tell it to *only* search for
tags that start with `v`, so that it will ignore `releases/latest`.

`spack -V` also would print out unwanted git eror output on a shallow
clone.

- [x] add `--match 'v*'` to `git describe` arguments
- [x] route error output to `os.devnull`

* Change buildcache create `NoOverwriteException` back to a warning.

* Hotfix: move CUDAHOSTCXX

Set only in dependent packages.

* dependent compiler

`spack buildcache list` was trying to construct an `Arch` object and
compare it to `arch_for_spec(<spec>)`. for each spec in the buildcache.
`Arch` objects are only intended to be constructed for the machine they
describe. The `ArchSpec` object (part of the `Spec`) is the descriptor
that lets us talk about architectures anywhere.

- [x] Modify `spack buildcache list` and `spack buildcache install` to
      filter with `Spec` matching instead of using `Arch`.

- [x] Make it easier to get a `Spec` with a proper `ArchSpec` from an
      `Arch` object via new `Arch.to_spec()` method.

- [x] Pull `spack.architecture.default_arch()` out of
      `spack.architecture.sys_type()` so we can get an `Arch` instead of
      a string.

* Loosen Axom's variants, add shared variant for axom, fix clang/xlf rpath'ing problem on blueos

* Fix flake8

* Add main branch to list of known git branches

fixes #18028

Since now external packages support multiple modules
the correct thing to do is to check if the name of the
*first* module to be loaded contains the string "cray"