Allow building fish as self-installable

CMakeLists.txt

@@ -63,6 +63,7 @@ function(FISH_LINK_DEPS_AND_SIGN target)
             build --bin ${target}
             $<$<CONFIG:Release,RelWithDebInfo>:--release>
             --target ${Rust_CARGO_TARGET}
+            --no-default-features
             ${CARGO_FLAGS}
             ${FEATURES_ARG}
       &&

Cargo.toml

@@ -38,6 +38,7 @@ once_cell = "1.17.0"
 rand = { version = "0.8.5", features = ["small_rng"] }
 widestring = "1.0.2"
 terminfo = { git = "https://github.com/meh/rust-terminfo", rev = "7259f5aa5786a9d396162da0d993e268f6163fb2" }
+rust-embed = { version = "8.2.0", optional = true }
 
 [dev-dependencies]
 rand_pcg = "0.3.1"
@@ -64,8 +65,9 @@ name = "fish_key_reader"
 path = "src/bin/fish_key_reader.rs"
 
 [features]
-default = []
+default = ["installable"]
 benchmark = []
+installable = ["dep:rust-embed"]
 
 # The following features are auto-detected by the build-script and should not be enabled manually.
 asan = []

build.rs

@@ -176,7 +176,14 @@ fn setup_paths() {
         var
     }
 
-    let prefix = PathBuf::from(env::var("PREFIX").unwrap_or("/usr/local".to_string()));
+    let (prefix_from_home, prefix) = if let Ok(pre) = env::var("PREFIX") {
+        (false, PathBuf::from(pre))
+    } else if let Ok(home) = env::var("HOME") {
+        (true, PathBuf::from(home).join(".local/"))
+    } else {
+        panic!("Need either $PREFIX or $HOME");
+    };
+
     if prefix.is_relative() {
         panic!("Can't have relative prefix");
     }
@@ -187,11 +194,24 @@ fn setup_paths() {
     rsconf::set_env_value("DATADIR", datadir.to_str().unwrap());
     rsconf::rebuild_if_env_changed("DATADIR");
 
+    let datadir_subdir = if prefix_from_home {
+        "fish/install"
+    } else {
+        "fish"
+    };
+    rsconf::set_env_value("DATADIR_SUBDIR", datadir_subdir);
+
     let bindir = get_path("BINDIR", "bin/", prefix.clone());
     rsconf::set_env_value("BINDIR", bindir.to_str().unwrap());
     rsconf::rebuild_if_env_changed("BINDIR");
 
-    let sysconfdir = get_path("SYSCONFDIR", "etc/", datadir.clone());
+    let sysconfdir = get_path(
+        "SYSCONFDIR",
+        // If we get our prefix from $HOME, we should use the system's /etc/
+        // ~/.local/share/etc/ makes no sense
+        if prefix_from_home { "/etc/" } else { "etc/" },
+        datadir.clone(),
+    );
     rsconf::set_env_value("SYSCONFDIR", sysconfdir.to_str().unwrap());
     rsconf::rebuild_if_env_changed("SYSCONFDIR");
 

share/functions/fish_config.fish

@@ -17,6 +17,8 @@ function fish_config --description "Launch fish's web based configuration"
     # Also opened with just `fish_config` or `fish_config browse`.
     if contains -- $cmd browse
         set -lx __fish_bin_dir $__fish_bin_dir
+        set -l fish_path (status fish-path)
+        and set __fish_bin_dir (path dirname -- $fish_path)
         if set -l python (__fish_anypython)
             $python "$__fish_data_dir/tools/web_config/webconfig.py" $argv