chore: upgrade nix to 0.29

This patch updates our nix dependency to 0.29.
We didn't have to do anything for libshpool, but
I had to make some tweaks to the test code. I
was even able to delete an `unsafe` block, which
is always nice.

libshpool/Cargo.toml

@@ -47,7 +47,7 @@ shpool-protocol = { version = "0.2.1", path = "../shpool-protocol" } # client-se
 
 # rusty wrapper for unix apis
 [dependencies.nix]
-version = "0.28"
+version = "0.29"
 features = ["poll", "ioctl", "socket", "user", "process", "signal", "term", "fs"]
 
 [dependencies.tracing-subscriber]

shpool/Cargo.toml

@@ -23,8 +23,12 @@ libshpool = { version = "0.8.1", path = "../libshpool" }
 [dev-dependencies]
 lazy_static = "1" # globals
 crossbeam-channel = "0.5" # channels
-nix = { version = "0.26", features = ["poll", "ioctl"] } # rusty wrapper for unix apis
 tempfile = "3" # keeping tests hermetic
 regex = "1" # test assertions
 serde_json = "1" # json parsing
 ntest = "0.9" # test timeouts
+
+# rusty wrapper for unix apis
+[dependencies.nix]
+version = "0.29"
+features = ["poll", "ioctl", "process", "signal", "fs"]

shpool/tests/daemon.rs

@@ -2,7 +2,7 @@ use std::{
     fmt::Write,
     io::Read,
     os::unix::{
-        io::{AsRawFd, FromRawFd},
+        io::AsRawFd,
         net::UnixListener,
         process::CommandExt as _,
     },
@@ -80,8 +80,7 @@ fn systemd_activation() -> anyhow::Result<()> {
 
         let (parent_stderr, child_stderr) =
             nix::unistd::pipe().context("creating pipe to collect stderr")?;
-        // Safety: this is a test
-        let child_stderr_pipe = unsafe { Stdio::from_raw_fd(child_stderr) };
+        let child_stderr_pipe = Stdio::from(child_stderr);
         let mut cmd = Command::new(support::shpool_bin()?);
         cmd.stdout(Stdio::piped())
             .stderr(child_stderr_pipe)
@@ -147,8 +146,9 @@ fn systemd_activation() -> anyhow::Result<()> {
         nix::sys::wait::waitpid(child_pid, None).context("reaping daemon")?;
 
         let mut stderr_buf: Vec<u8> = vec![0; 1024 * 8];
-        let len =
-            nix::unistd::read(parent_stderr, &mut stderr_buf[..]).context("reading stderr")?;
+        let len = nix::unistd::read(
+            parent_stderr.as_raw_fd(),
+            &mut stderr_buf[..]).context("reading stderr")?;
         let stderr = String::from_utf8_lossy(&stderr_buf[..len]);
         assert!(stderr.contains("using systemd activation socket"));