CI: Switch tooling setup to Nix

.justfile

@@ -81,7 +81,7 @@ msrv-find:
 
 make_msrv(command, target) := f"printf '{{ target }}: '; " + \
     f"cargo msrv {{ command }} --target {{ target }} --output-format minimal " \
-    + f"-- {{ maybe_xwin(target) }} build --ignore-rust-version"
+    + f"-- {{ xwin_if(target) }} build --ignore-rust-version"
 
 [private]
 test-cover-quick:
@@ -466,15 +466,21 @@ alias bm := build-musl
 # Release build
 [group: 'build']
 release-build target=default_target:
-    {{ maybe_xwin(target) }} build \
+    {{ xwin_if(target) }} build \
         --timings --target {{ target }} --locked --release
     du -h target/{{ target }}/release/{{ with_suffix("en", target) }}
 
-maybe_xwin(target) := if target == msvc_target { "cargo-xwin" } else { "cargo" }
+xwin_if(target) := if target == msvc_target { "cargo-xwin" } else { "cargo" }
 with_suffix(file, target) := if target == msvc_target { f"{{ file }}.exe" } else { file }
 
 alias rb := release-build
 
+# Release build of all targets
+[group: 'build']
+release-build-all: release-build-musl release-build-gnu release-build-msvc
+
+alias rba := release-build-all
+
 # glibc release build
 [group: 'build']
 release-build-gnu:
@@ -521,9 +527,18 @@ choose:
 
 alias ch := choose
 
-[script, private, env("CARGO_HOME", "$HOME/.cargo")]
-ci recipe:
-    su ci -c "just {{ recipe }}"
+[script, private]
+ci recipes:
+    ENV_PATH="$PATH" su ci -c "{{ just_cmd }} -f '{{ justfile() }}' {{ recipes }}"
+
+[script, private]
+ci-nix recipes:
+    ENV_PATH="$PATH" su ci -c "nix develop --command \
+        {{ just_cmd }} -f '{{ justfile() }}' {{ recipes }}"
+
+[private]
+smoke:
+    echo OK
 
 ## VARIABLES
 export CARGO_TERM_COLOR := 'always'