fix(serve): Don't offer unused --destination

Fixes #1189

Author: epage

src/bin/cobalt/args.rs

@@ -11,10 +11,6 @@ pub(crate) struct ConfigArgs {
     #[arg(short, long, value_name = "FILE")]
     config: Option<path::PathBuf>,
 
-    /// Site destination folder [default: ./_site]
-    #[arg(short, long, value_name = "DIR")]
-    destination: Option<path::PathBuf>,
-
     /// Include drafts.
     #[arg(long)]
     drafts: bool,
@@ -37,15 +33,6 @@ impl ConfigArgs {
             cobalt_config::Config::from_cwd(".")?
         };
 
-        config.abs_dest = self
-            .destination
-            .as_deref()
-            .map(|d| {
-                std::fs::create_dir_all(d)?;
-                dunce::canonicalize(d)
-            })
-            .transpose()?;
-
         if let Some(drafts) = self.drafts() {
             config.include_drafts = drafts;
         }

src/bin/cobalt/build.rs

@@ -7,13 +7,26 @@ use crate::error::Result;
 /// Build the cobalt project at the source dir
 #[derive(Clone, Debug, PartialEq, Eq, clap::Args)]
 pub(crate) struct BuildArgs {
+    /// Site destination folder [default: ./_site]
+    #[arg(short, long, value_name = "DIR", help_heading = "Config")]
+    destination: Option<std::path::PathBuf>,
+
     #[command(flatten, next_help_heading = "Config")]
     pub(crate) config: args::ConfigArgs,
 }
 
 impl BuildArgs {
     pub(crate) fn run(&self) -> Result<()> {
-        let config = self.config.load_config()?;
+        let mut config = self.config.load_config()?;
+        config.abs_dest = self
+            .destination
+            .as_deref()
+            .map(|d| {
+                fs::create_dir_all(d)?;
+                dunce::canonicalize(d)
+            })
+            .transpose()?;
+
         let config = cobalt::cobalt_model::Config::from_config(config)?;
 
         build(config)?;