version: prepare for 1.9.0-alpha20240404 release

CHANGELOG.md

@@ -1,4 +1,4 @@
-## 1.9.0 (Unreleased)
+## 1.9.0-alpha20240404 (April 4, 2024)
 
 ENHANCEMENTS:
 
@@ -8,18 +8,16 @@ ENHANCEMENTS:
 
 BUG FIXES:
 
-* `remote-exec`: Each remote connection will be closed immediately after use [GH-34137]
-* `backend/s3`: Fixed the digest value displayed for DynamoDB/S3 state checksum mismatches [GH-34387]
+* `remote-exec`: Each remote connection will be closed immediately after use ([#34137](https://github.com/hashicorp/terraform/issues/34137))
+* `backend/s3`: Fixed the digest value displayed for DynamoDB/S3 state checksum mismatches ([#34387](https://github.com/hashicorp/terraform/issues/34387))
 
 EXPERIMENTS:
 
 Experiments are only enabled in alpha releases of Terraform CLI. The following features are not yet available in stable releases.
 
 * `terraform test` accepts a new option `-junit-xml=FILENAME`. If specified, and if the test configuration is valid enough to begin executing, then Terraform writes a JUnit XML test result report to the given filename, describing similar information as included in the normal test output. ([#34291](https://github.com/hashicorp/terraform/issues/34291))
 * The new command `terraform rpcapi` exposes some Terraform Core functionality through an RPC interface compatible with [`go-plugin`](https://github.com/hashicorp/go-plugin). The exact RPC API exposed here is currently subject to change at any time, because it's here primarily as a vehicle to support the [Terraform Stacks](https://www.hashicorp.com/blog/terraform-stacks-explained) private preview and so will be broken if necessary to respond to feedback from private preview participants, or possibly for other reasons. Do not use this mechanism yet outside of Terraform Stacks private preview.
-* The [language-level experiment](https://developer.hashicorp.com/terraform/language/settings#experimental-language-features) `unknown_instances` permits `count` and `for_each` arguments in `module`, `resource`, and `data` blocks to have unknown values.
-
-    This is at an early stage and so currently setting these arguments to unknown values will only yield broken behavior, and so it's not yet useful to participate in this experiment. Future work will improve support for this new possibility, gradually making this experiment viable.
+* The experimental "deferred actions" feature, enabled by passing the `-allow-deferral` option to `terraform plan`, permits `count` and `for_each` arguments in `module`, `resource`, and `data` blocks to have unknown values and allows providers to react more flexibly to unknown values. This experiment is under active development, and so it's not yet useful to participate in this experiment. 
 
 ## Previous Releases
 

version/VERSION

@@ -1 +1 @@
-1.9.0-dev
+1.9.0-alpha20240404