Bump the Rust requirement to 1.68

1.63 is quite old at this point, and 1.68 allows us to take advantage of
the sparse index format, speeding up CI. This shouldn't matter much in
terms of ease of use, as up-to-date distributions ship 1.68 or newer,
and slower to update ones (e.g. Debian) didn't even ship 1.63 to begin
with.

Changelog: changed

.github/workflows/freebsd.yml

@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.63'
+          - '1.68'
           - stable
     runs-on: macos-latest
     steps:
@@ -47,7 +47,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.63'
+          - '1.68'
           - stable
     runs-on: macos-latest
     needs:

.github/workflows/lint.yml

@@ -48,9 +48,9 @@ jobs:
           path: |
             ${{ env.CARGO_HOME }}
             target
-          key: ubuntu-1.63
+          key: ubuntu-1.68
       - name: Installing Rust
-        run: ./scripts/rust.sh 1.63
+        run: ./scripts/rust.sh 1.68
       - name: Installing LLVM
         run: ./scripts/llvm.sh ubuntu
       - name: Installing clippy

.github/workflows/linux.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.63'
+          - '1.68'
           - stable
     runs-on: ubuntu-latest
     steps:
@@ -36,7 +36,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.63'
+          - '1.68'
           - stable
     runs-on: ubuntu-latest
     needs:

.github/workflows/mac.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.63'
+          - '1.68'
           - stable
     runs-on: macos-latest
     steps:
@@ -36,7 +36,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.63'
+          - '1.68'
           - stable
     runs-on: macos-latest
     needs:

docs/source/getting-started/installation.md

@@ -21,7 +21,7 @@ changes.
 ## Requirements
 
 - A 64-bits little-endian platform
-- Rust 1.63 or newer
+- Rust 1.68 or newer
 - LLVM 15, with support for static linking against LLVM
 - A C compiler such as [GCC](https://gcc.gnu.org/) or
   [clang](https://clang.llvm.org/)

docs/source/getting-started/ivm.md

@@ -6,7 +6,7 @@ in Rust.
 
 ## Installing
 
-ivm itself only requires Rust 1.63 or newer, but to build Inko itself you'll
+ivm itself only requires Rust 1.68 or newer, but to build Inko itself you'll
 need to also meet the requirements listed in the [installation
 guide](installation.md).