Refresh the CI matrix and fix warning in tests/MakeAbsolute.hs

- The matrix has been updated to include the most recent versions of GHC
  and Cabal.
- Some of the versions in between the oldest and newest have been
  dropped to reduce CI workload.
- Fixed a warning in tests/MakeAbsolute.hs due to use of partial
  function "head".

Fixes #205.

Author: Rufflewind

.github/workflows/build.yml

@@ -17,17 +17,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { os: macOS-14, stack: lts-20.26, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.5.2.0, os-string-2.0.2, unix-2.8.5.1", stack-package-flags: "{file-io: {os-string: true}, unix: {os-string: true}}" }
+          - { os: macos-latest, stack: lts-20.26, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.5.2.0, os-string-2.0.2, unix-2.8.5.1", stack-package-flags: "{file-io: {os-string: true}, unix: {os-string: true}}" }
           - { os: macos-latest, stack: lts-24.29, ghc-flags: -Werror=deprecations }
           - { os: ubuntu-latest, ghc: 8.10.7, cabal: 3.8.1.0 }
-          - { os: ubuntu-latest, ghc: 9.0.2, cabal: 3.8.1.0 }
-          - { os: ubuntu-latest, ghc: 9.2.4, cabal: 3.8.1.0 }
-          - { os: ubuntu-latest, ghc: 9.4.3, cabal: 3.8.1.0, upload-sdist: true }
-          # TODO: Unpin cabal from 3.12.10 after https://github.com/haskell/cabal/issues/10718 is fixed.
-          - { os: ubuntu-latest, ghc: latest, cabal: 3.12.1.0, cabal-package-flags: +os-string, ghc-flags: -Werror=deprecations }
-          - { os: windows-latest, stack: lts-15.3, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.4.100.0, time-1.9.3, Win32-2.14.1.0", overrides: "before_prepare() { sed -i.bak -e /CreateSymbolicLinkW/d -e /GetFinalPathNameByHandleW/d configure.ac; }" }
-          - { os: windows-latest, stack: lts-17.5, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.4.100.0, time-1.9.3, Win32-2.14.1.0" }
-          - { os: windows-latest, stack: lts-22.7, stack-extra-deps: "bytestring-0.11.5.3, file-io-0.1.4, filepath-1.5.2.0, os-string-2.0.2, time-1.14, Win32-2.14.1.0", stack-package-flags: "{file-io: {os-string: true}, Win32: {os-string: true}}", ghc-flags: -Werror=deprecations }
+          - { os: ubuntu-latest, ghc: 9.4.8, cabal: 3.12.1.0 }
+          - { os: ubuntu-latest, ghc: latest, cabal: 3.16.1.0, upload-sdist: true, ghc-flags: -Werror=deprecations }
+          - { os: windows-latest, stack: lts-16.31, stack-extra-deps: "bytestring-0.11.3.0, file-io-0.1.4, filepath-1.4.100.0, time-1.9.3, Win32-2.14.1.0", overrides: "before_prepare() { sed -i.bak -e /CreateSymbolicLinkW/d -e /GetFinalPathNameByHandleW/d configure.ac; }" }
+          - { os: windows-latest, stack: lts-24.29, ghc-flags: -Werror=deprecations }
     runs-on: ${{ matrix.os }}
     env:
       CABAL_PACKAGE_FLAGS: ${{ matrix.cabal-package-flags }}

tests/MakeAbsolute.hs

@@ -43,7 +43,8 @@ main _t = do
 
 #if defined(mingw32_HOST_OS)
   cwd <- getCurrentDirectory
-  let driveLetter = toUpper (toChar (head (unpack (takeDrive cwd))))
+  cwdDriveLetter : _ <- pure (unpack (takeDrive cwd))
+  let driveLetter = toUpper (toChar cwdDriveLetter)
   let driveLetter' = if driveLetter == 'Z' then 'A' else succ driveLetter
   drp1 <- makeAbsolute (os (driveLetter : ":foobar"))
   drp2 <- makeAbsolute (os (driveLetter' : ":foobar"))