* Simplified the spack.util.gpg implementation
All the classes defined in this Python module,
which were previously used to construct singleton
instances, have been removed in favor of four
global variables. These variables are initialized
lazily, like before.
The API of the module has been unchanged for the
most part. A few tests have been modified to use
the new global names.
1. add version 2021.05.15.
2. add patch to build old revs with gcc 11.x, version 2021.15.05
already has patch integrated, fixes#23667.
3. add variant +debug to build unoptimized, debug version.
4. add variant +viewer to include hpcviewer and add viewer path to
hpctoolkit module.
5. add dependency on memkind to workaround a glibc problem found on
some Cray platforms.
For me the buildcache force overwrite option does not work. It tries to
delete a file, but errors with a key error, apparently because the
leading / has to be removed.
* util.tty.log: read up to 100 lines if ready
Rework to read up to 100 lines from the captured stdin as long as data
is ready to be read immediately. Adds a helper function to poll with
`select` for ready data. This showed a roughly 5-10x perf improvement
for high-rate writes through the logger with relatively short lines.
* util.tty.log: Defer flushes to end of ready reads
Rather than flush per line, flush per set of reads. Since this is a
non-blocking loop, the total perceived wait is short.
* util.tty.log: only scan each line once, usually
Rather than always find all control characters then substitute them all,
use `subn` to count the number of control characters replaced. Only if
control characters exist find out what they are. This could be made
truly single pass with sub with a function, but it's a more intrusive
change and this got 99%ish of the performance improvement (roughly
another 2x in some cases).
* util.tty.log: remove check for `readable`
Python < 3 does not support a readable check on streams, should not be
necessary here since we control the only use and it's explicitly a
stream to be read.
* e4s ci: enable full e4s
* add llvm-amdgpu to list of specs needing an xlarge tagged runner
* comment out qt and qwt because of intermittent build failures
* remove +rocm specs because rocblas job consistently fails due to infrastructure
