revert implementation

cmd/crates/soroban-test/tests/it/build.rs

@@ -186,7 +186,7 @@ fn with_flags(expected: &str) -> String {
             .split("\n")
             .map(|x| {
                 format!(
-                    "CARGO_BUILD_RUSTFLAGS='--remap-path-prefix {}=' {}",
+                    "CARGO_BUILD_RUSTFLAGS=--remap-path-prefix={}= {}",
                     registry_prefix, x
                 )
             })

cmd/soroban-cli/src/commands/contract/build.rs

@@ -323,9 +323,8 @@ impl Cmd {
 /// debugging is expected to be minimal.
 ///
 /// This works by setting the `CARGO_BUILD_RUSTFLAGS` environment variable,
-/// with an appropriate
-/// [`--remap-path-prefix`](https://doc.rust-lang.org/rustc/command-line-arguments.html#--remap-path-prefix-remap-source-names-in-output)
-/// option. It preserves the values of an existing `CARGO_BUILD_RUSTFLAGS` environment variable.
+/// with appropriate `--remap-path-prefix` option. It preserves the values of an
+/// existing `CARGO_BUILD_RUSTFLAGS` environment variable.
 ///
 /// This must be done some via some variation of `RUSTFLAGS` and not as
 /// arguments to `cargo rustc` because the latter only applies to the crate
@@ -379,11 +378,9 @@ fn make_rustflags_to_remap_absolute_paths(print: &Print) -> Result<Option<String
     }
 
     let registry_prefix = format!("{cargo_home}/registry/src/");
-    let new_rustflag = format!("{registry_prefix}=");
+    let new_rustflag = format!("--remap-path-prefix={registry_prefix}=");
 
     let mut rustflags = get_rustflags().unwrap_or_default();
-    // --remap-path-prefix is separated by space with the arguments
-    rustflags.push("--remap-path-prefix".to_string());
     rustflags.push(new_rustflag);
 
     let rustflags = rustflags.join(" ");