Add a "require" directive to packages, which functions exactly like
requirements specified in packages.yaml (uses the same fact-generation
logic); update both to allow making the requirement conditional.
* Packages may now use "require" to add constraints. This can be useful
for something like "require(%gcc)" (where before we had to add a
conflict for every compiler except gcc).
* Requirements (in packages.yaml or in a "require" directive) can be
conditional on a spec, e.g. "require(%gcc, when=@1.0.0)" (version
1.0.0 can only build with gcc).
* Requirements may include a message which clarifies why they are needed.
The concretizer assigns a high priority to errors which generate these
messages (in particular over errors for unsatisfied requirements that
do not produce messages, but also over a number of more-generic
errors).
## Version types, parsing and printing
- The version classes have changed: `VersionBase` is removed, there is now a
`ConcreteVersion` base class. `StandardVersion` and `GitVersion` both inherit
from this.
- The public api (`Version`, `VersionRange`, `ver`) has changed a bit:
1. `Version` produces either `StandardVersion` or `GitVersion` instances.
2. `VersionRange` produces a `ClosedOpenRange`, but this shouldn't affect the user.
3. `ver` produces any of `VersionList`, `ClosedOpenRange`, `StandardVersion`
or `GitVersion`.
- No unexpected type promotion, so that the following is no longer an identity:
`Version(x) != VersionRange(x, x)`.
- `VersionList.concrete` now returns a version if it contains only a single element
subtyping `ConcreteVersion` (i.e. `StandardVersion(...)` or `GitVersion(...)`)
- In version lists, the parser turns `@x` into `VersionRange(x, x)` instead
of `Version(x)`.
- The above also means that `ver("x")` produces a range, whereas
`ver("=x")` produces a `StandardVersion`. The `=` is part of _VersionList_
syntax.
- `VersionList.__str__` now outputs `=x.y.z` for specific version entries,
and `x.y.z` as a short-hand for ranges `x.y.z:x.y.z`.
- `Spec.format` no longer aliases `{version}` to `{versions}`, but pulls the
concrete version out of the list and prints that -- except when the list is
is not concrete, then is falls back to `{versions}` to avoid a pedantic error.
For projections of concrete specs, `{version}` should be used to render
`1.2.3` instead of `=1.2.3` (which you would get with `{versions}`).
The default `Spec` format string used in `Spec.__str__` now uses
`{versions}` so that `str(Spec(string)) == string` holds.
## Changes to `GitVersion`
- `GitVersion` is a small wrapper around `StandardVersion` which enriches it
with a git ref. It no longer inherits from it.
- `GitVersion` _always_ needs to be able to look up an associated Spack version
if it was not assigned (yet). It throws a `VersionLookupError` whenever `ref_version`
is accessed but it has no means to look up the ref; in the past Spack would
not error and use the commit sha as a literal version, which was incorrect.
- `GitVersion` is never equal to `StandardVersion`, nor is satisfied by it. This
is such that we don't lose transitivity. This fixes the following bug on `develop`
where `git_version_a == standard_version == git_version_b` does not imply
`git_version_a == git_version_b`. It also ensures equality always implies equal
hash, which is also currently broken on develop; inclusion tests of a set of
versions + git versions would behave differently from inclusion tests of a
list of the same objects.
- The above means `ver("ref=1.2.3) != ver("=1.2.3")` could break packages that branch
on specific versions, but that was brittle already, since the same happens with
externals: `pkg@1.2.3-external` suffixes wouldn't be exactly equal either. Instead,
those checks should be `x.satisfies("@1.2.3")` which works both for git versions and
custom version suffixes.
- `GitVersion` from commit will now print as `<hash>=<version>` once the
git ref is resolved to a spack version. This is for reliability -- version is frozen
when added to the database and queried later. It also improves performance
since there is no need to clone all repos of all git versions after `spack clean -m`
is run and something queries the database, triggering version comparison, such
as potentially reuse concretization.
- The "empty VerstionStrComponent trick" for `GitVerison` is dropped since it wasn't
representable as a version string (by design). Instead, it's replaced by `git`,
so you get `1.2.3.git.4` (which reads 4 commits after a tag 1.2.3). This means
that there's an edge case for version schemes `1.1.1`, `1.1.1a`, since the
generated git version `1.1.1.git.1` (1 commit after `1.1.1`) compares larger
than `1.1.1a`, since `a < git` are compared as strings. This is currently a
wont-fix edge case, but if really required, could be fixed by special casing
the `git` string.
- Saved, concrete specs (database, lock file, ...) that only had a git sha as their
version, but have no means to look the effective Spack version anymore, will
now see their version mapped to `hash=develop`. Previously these specs
would always have their sha literally interpreted as a version string (even when
it _could_ be looked up). This only applies to databases, lock files and spec.json
files created before Spack 0.20; after this PR, we always have a Spack version
associated to the relevant GitVersion).
- Fixes a bug where previously `to_dict` / `from_dict` (de)serialization would not
reattach the repo to the GitVersion, causing the git hash to be used as a literal
(bogus) version instead of the resolved version. This was in particularly breaking
version comparison in the build process on macOS/Windows.
## Installing or matching specific versions
- In the past, `spack install pkg@3.2` would install `pkg@=3.2` if it was a
known specific version defined in the package, even when newer patch releases
`3.2.1`, `3.2.2`, `...` were available. This behavior was only there because
there was no syntax to distinguish between `3.2` and `3.2.1`. Since there is
syntax for this now through `pkg@=3.2`, the old exact matching behavior is
removed. This means that `spack install pkg@3.2` constrains the `pkg` version
to the range `3.2`, and `spack install pkg@=3.2` constrains it to the specific
version `3.2`.
- Also in directives such as `depends_on("pkg@2.3")` and their when
conditions `conflicts("...", when="@2.3")` ranges are ranges, and specific
version matches require `@=2.3.`.
- No matching version: in the case `pkg@3.2` matches nothing, concretization
errors. However, if you run `spack install pkg@=3.2` and this version
doesn't exist, Spack will define it; this allows you to install non-registered
versions.
- For consistency, you can now do `%gcc@10` and let it match a configured
`10.x.y` compiler. It errors when there is no matching compiler.
In the past it was interpreted like a specific `gcc@=10` version, which
would get bootstrapped.
- When compiler _bootstrapping_ is enabled, `%gcc@=10.2.0` can be used to
bootstrap a specific compiler version.
## Other changes
- Externals, compilers, and develop spec definitions are backwards compatible.
They are typically defined as `pkg@3.2.1` even though they should be
saying `pkg@=3.2.1`. Spack now transforms `pkg@3` into `pkg@=3` in those cases.
- Finally, fix strictness of `version(...)` directive/declaration. It just does a simple
type check, and now requires strings/integers. Floats are not allowed because
they are ambiguous `str(3.10) == "3.1"`.
`spack buildcache create` is a misnomer cause it's the only way to push to
an existing buildcache (and it in fact calls binary_distribution.push).
Also we have `spack buildcache update-index` but for create the flag is
`--rebuild-index`, which is confusing (and also... why "rebuild"
something if the command is "create" in the first place, that implies it
wasn't there to begin with).
So, after this PR, you can use either
```
spack buildcache create --rebuild-index
```
or
```
spack buildcache push --update-index
```
Also, alias `spack buildcache rebuild-index` to `spack buildcache
update-index`.
Spack never parsed `nagfor` linker arguments put on the compiler line:
```
nagfor -Wl,-Wl,,-rpath,,/path
````
so, let's continue not attempting to parse that.
