bwrap: Add set_default_path() helper for standard PATH

Extract the repeated PATH environment variable string into a
set_default_path() method on BwrapCmd. The bwrap environment may not
have a complete PATH, causing tools like bootupctl or sfdisk to not
be found. This consolidates the workaround into one place.

Assisted-by: OpenCode (Claude Opus 4)

Author: cgwalters

crates/lib/src/bootloader.rs

@@ -1,7 +1,7 @@
 use std::fs::create_dir_all;
 use std::process::Command;
 
-use anyhow::{Context, Result, anyhow, bail};
+use anyhow::{anyhow, bail, Context, Result};
 use bootc_utils::{BwrapCmd, CommandRunExt};
 use camino::Utf8Path;
 use cap_std_ext::cap_std::fs::Dir;
@@ -10,7 +10,7 @@ use fn_error_context::context;
 
 use bootc_mount as mount;
 
-use crate::bootc_composefs::boot::{SecurebootKeys, mount_esp};
+use crate::bootc_composefs::boot::{mount_esp, SecurebootKeys};
 use crate::{discoverable_partition_specification, utils};
 
 /// The name of the mountpoint for efi (as a subdirectory of /boot, or at the toplevel)
@@ -86,10 +86,7 @@ fn bootupd_supports_filesystem(rootfs: &Utf8Path, deployment_path: Option<&str>)
     let output = if let Some(deploy) = deployment_path {
         let target_root = rootfs.join(deploy);
         BwrapCmd::new(&target_root)
-            .setenv(
-                "PATH",
-                "/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/bin:/usr/local/sbin",
-            )
+            .set_default_path()
             .run_get_string(help_args)?
     } else {
         Command::new("bootupctl")
@@ -206,14 +203,8 @@ pub(crate) fn install_via_bootupd(
         }
 
         // The $PATH in the bwrap env is not complete enough for some images
-        // so we inject a reasonnable default.
-        // This is causing bootupctl and/or sfdisk binaries
-        // to be not found with fedora 43.
-        cmd.setenv(
-            "PATH",
-            "/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/bin:/usr/local/sbin",
-        )
-        .run(bwrap_args)
+        // so we inject a reasonable default.
+        cmd.set_default_path().run(bwrap_args)
     } else {
         // Running directly without chroot
         Command::new("bootupctl")

crates/utils/src/bwrap.rs

@@ -59,6 +59,18 @@ impl<'a> BwrapCmd<'a> {
         self
     }
 
+    /// Set $PATH to a reasonable default for finding system binaries.
+    ///
+    /// The bwrap environment may not have a complete $PATH, causing
+    /// tools like bootupctl or sfdisk to not be found. This sets a
+    /// default that covers the standard binary directories.
+    pub fn set_default_path(self) -> Self {
+        self.setenv(
+            "PATH",
+            "/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/bin:/usr/local/sbin",
+        )
+    }
+
     /// Build the bwrap `Command` with all bind mounts, env vars, and args.
     fn build_command<S: AsRef<OsStr>>(&self, args: impl IntoIterator<Item = S>) -> Command {
         let mut cmd = Command::new("bwrap");