fix: various small issues

README.md

@@ -42,7 +42,13 @@ cargo build --release
 # Optional: Install system-wide
 cargo install --path .
 
-# Optional: Build static binary
+# Optional: Build x86_64 static binary
+export CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER=x86_64-linux-gnu-gcc
+export CC=x86_64-linux-gnu-gcc
+rustup target add x86_64-unknown-linux-musl
+cargo build --target=x86_64-unknown-linux-musl
+
+# Optional: Build arm64 static binary
 export CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER=aarch64-linux-gnu-gcc
 export CC=aarch64-linux-gnu-gcc
 rustup target add aarch64-unknown-linux-musl

src/base_image.rs

@@ -96,7 +96,7 @@ where
         log::info!("removing current base image");
         for dir in dest.read_dir()? {
             let path = dir?.path();
-            if let Err(err) = chmod(&path, |mode| mode | 0o700) {
+            if let Err(err) = chmod_dirs(&path, |mode| mode | 0o700) {
                 log::error!(
                     "could not fix permissions for {}: {}",
                     path.display(),

src/image_builder.rs

@@ -97,7 +97,7 @@ impl BaseImageBuilder {
     }
 
     pub fn build_base_with_arch(&self, arch: &str) -> Result<()> {
-        install_nix(arch, &self.nix_dir)?;
+        install_nix(arch, &self.nix_dir).context("could not install Nix")?;
         log::info!("building base image");
 
         let tmp = tempdir()?;
@@ -406,6 +406,17 @@ pub fn chmod(path: &Path, func: fn(u32) -> u32) -> Result<(), io::Error> {
     Ok(())
 }
 
+pub fn chmod_dirs(path: &Path, func: fn(u32) -> u32) -> Result<(), io::Error> {
+    if fs::symlink_metadata(path)?.file_type().is_dir() {
+        for entry in path.read_dir()? {
+            chmod_dirs(&entry?.path(), func)?;
+        }
+        chmod_apply(path, func)?;
+    }
+
+    Ok(())
+}
+
 pub fn progress_bar(len: u64) -> ProgressBar {
     ProgressBar::new(len).with_style(
         ProgressStyle::with_template(
@@ -503,16 +514,20 @@ where
     let gcroots = dest.join("var/nix/gcroots");
     fs::create_dir_all(&gcroots)?;
 
-    if !nix_bin.exists() {
+    if !symlink_exists(&nix_bin) {
         let nix_store_path = find_nix(&nix_store, NIX_VERSION)?;
         let nix_path = Path::new("/nix/store").join(nix_store_path);
-        symlink(nix_path.join("bin"), nix_bin)?;
-        symlink(&nix_path, gcroots.join("nix"))?;
+        symlink(nix_path.join("bin"), nix_bin).unwrap();
+        symlink(&nix_path, gcroots.join("nix")).unwrap();
     }
 
     Ok(())
 }
 
+fn symlink_exists<P: AsRef<Path>>(path: P) -> bool {
+    fs::symlink_metadata(path).is_ok_and(|f| f.file_type().is_symlink())
+}
+
 fn symlink_base<P: AsRef<Path>>(base_path: P) -> Result<(), io::Error> {
     let base_link = Path::new("/nix/.base");
     let gcroots = Path::new("/nix/var/nix/gcroots");

src/pid_file.rs

@@ -24,7 +24,6 @@ impl PidFile {
 
 impl Drop for PidFile {
     fn drop(&mut self) {
-        log::debug!("removing {}", self.path.display());
         if let Err(err) = fs::remove_file(&self.path) {
             log::error!("while removing: {}", err);
         }

src/shell.rs

@@ -1,6 +1,7 @@
 use std::{
     collections::HashMap,
     ffi::{OsStr, OsString},
+    fs::create_dir_all,
     os::unix::process::CommandExt,
     process::{self, exit, Command},
 };
@@ -100,6 +101,7 @@ impl Shell {
             ("INFOPATH", format!("{nix_base}/share/info")),
         ]);
 
+        let _ = create_dir_all("/nix/.cache");
         let err = cmd.exec();
         bail!("cannot exec: {}", err)
     }