Merge remote-tracking branch 'alire/release/2.0'

Author: mosteo

RELEASING.md

@@ -1,5 +1,6 @@
 ## Checklist for releasing a new version
 
+1. [ ] Update version in `Alire.Version`.
 1. [ ] Create test release in own fork.
   - To verify builds succeed.
   - As the Windows build can rarely fail, this provides a backup .exe

doc/user-changes.md

@@ -49,6 +49,37 @@ automatic updates.
 When enabled, updates may happen before executing commands that rely on
 indexes: `get`, `search`, `with`, etc.
 
+### Enable shared dependencies by default
+
+PR [#1449](https://github.com/alire-project/alire/pull/1449)
+
+Pre-2.0, Alire worked always in "sandboxed" mode; that is, all source
+dependencies were found under `<workspace>/alire/cache`. This behavior can be
+now enabled with `alr config --set dependencies.shared false`, locally or
+globally.
+
+By default, post-2.0, Alire works in "shared" mode, where sources are
+downloaded once (to `~/.cache/alire/releases`) and unique builds are created
+(under `~/.cache/alire/builds`) for unique configurations. This should minimize
+rebuilds across crate configurations and workspaces, and eliminate risks of
+inconsistencies.
+
+Disk use is decreased by unique source downloads, but might be increased by
+unique build configurations. Cache management and cleanup will be provided down
+the road. The build cache can always be deleted to retrieve disk space, at the
+cost of triggering rebuilds.
+
+Unique builds are identified by a build hash which takes into account the
+following inputs for a given release:
+
+- Build profile
+- Environment variables modified in the manifest
+- GPR external variables declared or set
+- Configuration variables declared or set
+- Compiler version
+- Vaue of `LIBRARY_TYPE` and `<CRATE>_LIBRARY_TYPE` variables.
+- Hash of dependencies
+
 ### Deprecation of `dependencies.dir` in favor of `dependencies.shared`
 
 PR [#1419](https://github.com/alire-project/alire/pull/1419)

src/alire/alire-version.ads

@@ -2,7 +2,8 @@ package Alire.Version with Preelaborate is
 
    --  Remember to update Alire.Index branch if needed too
 
-   Current : constant String := "2.0-dev";
+   Current : constant String := "2.0-beta1";
+   --  2.0.0-b1:  first public release on the 2.0 branch
    --  1.2.1:     build switches fix and other minor assorted fixes
    --  1.2.0:     rpm speed-up, silence propagation warning, early switch parse
    --  1.2.0-rc1: release candidate for 1.2