feat: trace credential helper invocations. (#1103)

This should make it easier to understand what's going on in case
something isn't working as expected.

Author: Byron

Cargo.lock

@@ -13,6 +13,8 @@ include = ["src/lib.rs", "LICENSE-*"]
 doctest = false
 
 [dependencies]
+gix-trace = { version = "^0.1.3", path = "../gix-trace" }
+
 bstr = { version = "1.5.0", default-features = false, features = ["std"] }
 
 [dev-dependencies]

gix-command/Cargo.toml

@@ -93,7 +93,9 @@ mod prepare {
     impl Prepare {
         /// Spawn the command as configured.
         pub fn spawn(self) -> std::io::Result<std::process::Child> {
-            Command::from(self).spawn()
+            let mut cmd = Command::from(self);
+            gix_trace::debug!(cmd = ?cmd);
+            cmd.spawn()
         }
     }
 

gix-command/src/lib.rs

@@ -23,6 +23,7 @@ gix-path = { version = "^0.10.0", path = "../gix-path" }
 gix-command = { version = "^0.2.10", path = "../gix-command" }
 gix-config-value = { version = "^0.14.0", path = "../gix-config-value" }
 gix-prompt = { version = "^0.7.0", path = "../gix-prompt" }
+gix-trace = { version = "^0.1.3", path = "../gix-trace" }
 
 thiserror = "1.0.32"
 serde = { version = "1.0.114", optional = true, default-features = false, features = ["derive"] }

gix-credentials/Cargo.toml

@@ -106,6 +106,7 @@ impl Program {
                 Stdio::null()
             })
             .stderr(if self.stderr { Stdio::inherit() } else { Stdio::null() });
+        gix_trace::debug!(cmd = ?cmd, "launching credential helper");
         let mut child = cmd.spawn()?;
         let stdin = child.stdin.take().expect("stdin to be configured");
         let stdout = child.stdout.take();

gix-credentials/src/program/mod.rs

@@ -22,6 +22,7 @@ pub(crate) fn install_config_path() -> Option<&'static BStr> {
         cmd.args(["config", "-l", "--show-origin"])
             .stdin(Stdio::null())
             .stderr(Stdio::null());
+        gix_trace::debug!(cmd = ?cmd, "invoking git for installation config path");
         first_file_from_config_with_origin(cmd.output().ok()?.stdout.as_slice().into()).map(ToOwned::to_owned)
     });
     PATH.as_ref().map(AsRef::as_ref)

gix-path/src/env/git.rs

@@ -74,12 +74,10 @@ pub fn system_prefix() -> Option<&'static Path> {
                 }
             }
 
-            let path = std::process::Command::new("git.exe")
-                .arg("--exec-path")
-                .stderr(std::process::Stdio::null())
-                .output()
-                .ok()?
-                .stdout;
+            let mut cmd = std::process::Command::new("git.exe");
+            cmd.arg("--exec-path").stderr(std::process::Stdio::null());
+            gix_trace::debug!(cmd = ?cmd, "invoking git to get system prefix/exec path");
+            let path = cmd.output().ok()?.stdout;
             let path = BString::new(path)
                 .trim_with(|b| b.is_ascii_whitespace())
                 .to_path()

gix-path/src/env/mod.rs

@@ -107,7 +107,7 @@ pub fn connect(
     let ssh_cmd = options.ssh_command();
     let mut kind = options.kind.unwrap_or_else(|| ProgramKind::from(ssh_cmd));
     if options.kind.is_none() && kind == ProgramKind::Simple {
-        kind = if std::process::Command::from(
+        let mut cmd = std::process::Command::from(
             gix_command::prepare(ssh_cmd)
                 .stderr(Stdio::null())
                 .stdout(Stdio::null())
@@ -117,11 +117,9 @@ pub fn connect(
                 .arg(url.host_argument_safe().ok_or_else(|| Error::AmbiguousHostName {
                     host: url.host().expect("set in ssh urls").into(),
                 })?),
-        )
-        .status()
-        .ok()
-        .map_or(false, |status| status.success())
-        {
+        );
+        gix_features::trace::debug!(cmd = ?cmd, "invoking `ssh` for feature check");
+        kind = if cmd.status().ok().map_or(false, |status| status.success()) {
             ProgramKind::Ssh
         } else {
             ProgramKind::Simple