This commit extends the DSL that can be used in packages
to allow declaring that a package uses different build-systems
under different conditions.
It requires each spec to have a `build_system` single valued
variant. The variant can be used in many context to query, manipulate
or select the build system associated with a concrete spec.
The knowledge to build a package has been moved out of the
PackageBase hierarchy, into a new Builder hierarchy. Customization
of the default behavior for a given builder can be obtained by
coding a new derived builder in package.py.
The "run_after" and "run_before" decorators are now applied to
methods on the builder. They can also incorporate a "when="
argument to specify that a method is run only when certain
conditions apply.
For packages that do not define their own builder, forwarding logic
is added between the builder and package (methods not found in one
will be retrieved from the other); this PR is expected to be fully
backwards compatible with unmodified packages that use a single
build system.
Reworking lua to allow easier substitution of the base lua implementation.
Also adding in a maintained version of luajit and re-factoring the entire stack
to use a custom build-system to centralize functionality like environment
variable management and luarocks installation.
The `lua-lang` virtual is now versioned so that a package that requires
Lua 5.1 semantics can get any lua, but one that requires 5.2 will only
get upstream lua.
The luaposix package requires lua-bit32, but only when built with a
lua conforming to version 5.1. This adds the package, and the
dependencies, but exposed a problem with luarocks dependency
detection. Since we're installing each package in its own "tree" and
there's no environment variable to list extra trees, spack now
generates a luarocks config file that lists all the trees of all the
dependencies, and references it by setting `LUAROCKS_CONFIG`
in the build environment of every LuaPackage. This allows luarocks
to find the spack installed dependencies correctly rather than
trying (and failing) to download them.
Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>
Co-authored-by: Tom Scogland <tscogland@llnl.gov>
Co-authored-by: Massimiliano Culpo <massimiliano.culpo@gmail.com>
