Generate man pages

Cargo.toml

@@ -43,6 +43,7 @@ backoff = { version = "0.4.0", default-features = false }
 camino = "1.1.4"
 # Clap 4.4 is the last version supporting Rust 1.72.
 clap = { version = "~4.4", features = ["derive", "wrap_help", "env", "string"] }
+clap_mangen = { version = "=0.2.19", optional = true }
 clearscreen = "2.0.1"
 command-group = { version = "2.1.0", features = ["tokio", "with-tokio"] }
 crossterm = { version = "0.27.0", features = ["event-stream"] }

nix/packages/ghciwatch.nix

@@ -3,6 +3,7 @@
   stdenv,
   libiconv,
   darwin,
+  buildPackages,
   haskell,
   haskellPackages,
   ghc,
@@ -12,6 +13,7 @@
   rustPlatform,
   rust-analyzer,
   mdbook,
+  installShellFiles,
   # Versions of GHC to include in the environment for integration tests.
   # These should be attributes of `haskell.compiler`.
   ghcVersions ? null,
@@ -103,6 +105,9 @@
       inherit cargoArtifacts;
     };
 
+  can-run-ghciwatch = stdenv.hostPlatform.emulatorAvailable buildPackages;
+  run-ghciwatch = "${stdenv.hostPlatform.emulator buildPackages} $out/bin/ghciwatch";
+
   releaseArgs =
     commonArgs
     // {
@@ -119,8 +124,31 @@
       };
     };
 
+  ghciwatch-man = craneLib.buildPackage (releaseArgs
+    // {
+      pnameSuffix = "-man";
+
+      cargoExtraArgs = "--locked --features clap_mangen";
+
+      nativeBuildInputs = (releaseArgs.nativeBuildInputs or []) ++ [installShellFiles];
+
+      postInstall =
+        (releaseArgs.postInstall or "")
+        + lib.optionalString can-run-ghciwatch ''
+          manpages=$(mktemp -d)
+          ${run-ghciwatch} --generate-man-pages "$manpages"
+          for manpage in "$manpages"/*; do
+            installManPage "$manpage"
+          done
+
+          rm -rf "$out/bin"
+        '';
+    });
+
   ghciwatch-with-clap-markdown = craneLib.buildPackage (releaseArgs
     // {
+      pnameSuffix = "-cli-markdown";
+
       cargoExtraArgs = "--locked --features clap-markdown";
     });
 
@@ -245,4 +273,16 @@
     ];
   };
 in
-  craneLib.buildPackage releaseArgs
+  craneLib.buildPackage (releaseArgs
+    // {
+      postInstall =
+        (releaseArgs.postInstall or "")
+        + ''
+          cp -r ${ghciwatch-man}/share $out/share
+
+          # For some reason this is needed to strip references:
+          #     stripping references to cargoVendorDir from share/man/man1/ghciwatch.1.gz
+          #     sed: couldn't open temporary file share/man/man1/sedwVs75O: Permission denied
+          chmod -R +w $out/share
+        '';
+    })

src/cli.rs

@@ -100,6 +100,11 @@ pub struct Opts {
     #[arg(long, hide = true)]
     pub generate_markdown_help: bool,
 
+    /// Generate `man` pages in the given directory.
+    #[cfg(feature = "clap_mangen")]
+    #[arg(long, hide = true)]
+    pub generate_man_pages: Option<Utf8PathBuf>,
+
     /// Lifecycle hooks and commands to run at various points.
     #[command(flatten)]
     pub hooks: crate::hooks::HookOpts,

src/main.rs

@@ -30,6 +30,19 @@ async fn main() -> miette::Result<()> {
         return Ok(());
     }
 
+    #[cfg(feature = "clap_mangen")]
+    if let Some(out_dir) = opts.generate_man_pages {
+        use clap::CommandFactory;
+        use miette::IntoDiagnostic;
+        use miette::WrapErr;
+
+        let command = cli::Opts::command();
+        clap_mangen::generate_to(command, out_dir)
+            .into_diagnostic()
+            .wrap_err("Failed to generate man pages")?;
+        return Ok(());
+    }
+
     std::env::set_var("IN_GHCIWATCH", "1");
 
     let (ghci_sender, ghci_receiver) = mpsc::channel(32);