* CI: Fix CVE-2020-15228 in GitHub Actions
Fixes the CVE-2020-15228 security issue in GitHub Actions:
> `add-path` and `set-env` Runner commands are processed via stdout
set-env was used twice, which is now replaced by >> $GITHUB_ENV
- Issue: https://github.com/actions/toolkit/security/advisories/GHSA-mfwh-5m23-j46w
- Solution: https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-commands-for-github-actions#setting-an-environment-variable)
* CI: Specify installing libsigc++ v2.x in GitHub Actions
Version 3 of libsigc++ was automatically installed. This commit fixates the version brew installs to 2.x.
Should fix#6002
* CI: Use v2 checkout and upload-artifact actions
Also replaces macos-10.15 with macos-latest as runner. Currently is references the same environment (macOS 10.15), but this way it will update to macOS 11.0 when it's ready and stable.
* update macOS autobuild yaml
* updates */CMakeLists* for macOS autobuild compatibility
* "" a dir for cmake
* Un empty an empty EXTRA_INCDIR
* use a cmake operator
* Use the . dir to un-empty a string
* fix minutes timer in macos yaml
* test & skip instead of load & include
* disregard fractional part of minutes in mac yaml
* add another cmake test
* fix typo in mac yaml
* fix other part of same typo
* correct a filename in mac yaml
* test all include dirs
* fix of mac yaml
* mac:fix a path in yaml
* mac:and its antecedent
* options.h include a dir
* test __has_include (gcc 5.* & up & clang)
* remove a printf() in mac yaml
* mac:change a "" and an elseif() to else()
* fix a whitespace error
* fix 2 whitespace errors
* ZULU>UTC
* add a "UTC
* on the other side of the "
* mac:properly set default LOCAL_PREFIX in CACHE
* use of zsh subshells in macos yaml
* mac:remove some &&
* mac:remove some "
* mac:floating point divisors
* mac:use double paren (())
* mac:add a dir
* mac:floatize with decimal point
* mac:zsh -c certain lines
* remove a marker
