fetch ERANGE value from libc

Author: pvdrz

src/shims/env.rs

@@ -131,7 +131,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         // If we cannot get the current directory, we return null
         // FIXME: Technically we have to set the `errno` global too
         match env::current_dir() {
-            Ok(cwd) =>{
+            Ok(cwd) => {
                 // It is not clear what happens with non-utf8 paths here
                 let mut bytes = cwd.display().to_string().into_bytes();
                 // If the buffer is smaller or equal than the path, we return null.
@@ -142,7 +142,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                     this.memory_mut().get_mut(buf.alloc_id)?.write_bytes(tcx, buf, &bytes)?;
                     return Ok(Scalar::Ptr(buf))
                 }
-                this.machine.last_error = 34; // ERANGE
+                this.machine.last_error =
+                    this
+                    .eval_path_scalar(&["libc", "ERANGE"])?
+                    .unwrap()
+                    .to_u32()?;
             }
             Err(e) => this.machine.last_error = e.raw_os_error().unwrap() as u32,
         }