Quote WrappedCommand arguments with spaces in them

Otherwise, we are still not copy-paste friendly.

Ref: #174
Fixes: a0640aa ("Wrap std::process::Command to track arguments and environment variables")

src/lib.rs

@@ -227,6 +227,21 @@ impl WrappedCommand {
     }
 }
 
+/// Quote an argument that has spaces in it.
+/// When our `WrappedCommand` is printed to the terminal, arguments that contain spaces needed to be quoted.
+/// Otherwise, we will have output such as:
+/// `pkg-config --libs --cflags foo foo < 3.11`
+/// which cannot be used in a terminal - it will attempt to read a file named 3.11 and provide it as stdin for pkg-config.
+/// Using this function, we instead get the correct output:
+/// `pkg-config --libs --cflags foo 'foo < 3.11'`
+fn quote_if_needed(arg: String) -> String {
+    if arg.contains(' ') {
+        format!("'{}'", arg)
+    } else {
+        arg
+    }
+}
+
 /// Output a command invocation that can be copy-pasted into the terminal.
 /// `Command`'s existing debug implementation is not used for that reason,
 /// as it can sometimes lead to output such as:
@@ -248,7 +263,7 @@ impl Display for WrappedCommand {
         let args = self
             .args
             .iter()
-            .map(|arg| arg.to_string_lossy().to_string())
+            .map(|arg| quote_if_needed(arg.to_string_lossy().to_string()))
             .collect::<Vec<String>>()
             .join(" ");