xso-proc: work around regression in rustc nightly

Jonas Schäfer created

skip-changelog, this is no user-facing change.

See-Also: https://github.com/rust-lang/rust/issues/140585

Change summary

xso-proc/src/compound.rs | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)

Detailed changes

xso-proc/src/compound.rs 🔗

@@ -278,15 +278,29 @@ impl Compound {
                     format!("{}", name_b)
                 };
 
-                let field_a = FieldName(&member_a).to_string();
-                let field_b = FieldName(&member_b).to_string();
+                // See TODO below for why we do the extra replace calls.
+                let attr_a = attr_a.replace('{', "{{").replace('}', "}}");
+                let attr_b = attr_b.replace('{', "{{").replace('}', "}}");
+                let field_a = FieldName(&member_a)
+                    .to_string()
+                    .replace('{', "{{")
+                    .replace('}', "}}");
+                let field_b = FieldName(&member_b)
+                    .to_string()
+                    .replace('{', "{{")
+                    .replace('}', "}}");
 
                 // By assigning the checks to a `const`, we ensure that they
                 // are in fact evaluated at compile time, even if that constant
                 // is never used.
                 checks.extend(quote_spanned! {span=>
                     const _: () = { if #check {
-                        panic!("member {} and member {} match the same XML attribute: {} == {}", #field_a, #field_b, #attr_a, #attr_b);
+                        // TODO: Rust nightly from 2025-05-02 (or around that date) didn't like our fancy panic, so we use something simpler.
+                        // Filed bug upstream: https://github.com/rust-lang/rust/issues/140585
+                        // For now, we work around this because it breaks our docs builds...
+                        //panic!("member {} and member {} match the same XML attribute: {} == {}", #field_a, #field_b, #attr_a, #attr_b);
+                        // Note that we cannot replace it with concat!(..), because we may have `{` and `}` in the strings...
+                        panic!(concat!("member ", #field_a, " and member ", #field_b, " match the same XML attribute: ", #attr_a, " == ", #attr_b));
                     } };
                 })
             }