give context for errors in conditionals

1 files changed, 9 insertions, 5 deletions

diff --git a/src/makefile/input.rs b/src/makefile/input.rs
index 3707aef..316968f 100644
--- a/src/makefile/input.rs
+++ b/src/makefile/input.rs
@@ -331,11 +331,15 @@ impl<'a, 'parent, R: BufRead> MakefileReader<'a, 'parent, R> {
                     Err(err) => return Some((line_number, Err(err))),
                 };
                 if let Some(line) = cond_line {
-                    let action = line.action(
-                        self.conditional_stack.last(),
-                        |name| self.macros.is_defined(name),
-                        |t| self.expand_macros(t),
-                    );
+                    let action = line
+                        .action(
+                            self.conditional_stack.last(),
+                            |name| self.macros.is_defined(name),
+                            |t| self.expand_macros(t),
+                        )
+                        .wrap_err_with(|| {
+                            format!("while applying conditional on line {}", line_number)
+                        });
                     let action = match action {
                         Ok(x) => x,
                         Err(err) => return Some((line_number, Err(err))),