From 9c2c4d5d19b7b1b6b2502d747bc28c71764d66f3 Mon Sep 17 00:00:00 2001
From: Heath Stewart <heaths@outlook.com>
Date: Tue, 11 Nov 2025 12:52:40 -0800
Subject: [PATCH] Resolve CARGO_MANIFEST_DIR at runtime

Fix issue when used outside this repo.
---
 Cargo.lock | 2 +-
 Cargo.toml | 2 +-
 src/lib.rs | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6961a58..af8a768 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,7 +4,7 @@ version = 4
 
 [[package]]
 name = "include-file"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/Cargo.toml b/Cargo.toml
index e87aa96..67b8c9c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "include-file"
-version = "0.3.0"
+version = "0.4.0"
 description = "Include sections of files into Rust source code"
 readme = "README.md"
 authors = ["Heath Stewart (https://github.com/heaths)"]
diff --git a/src/lib.rs b/src/lib.rs
index cf4625e..d623189 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,7 +12,7 @@ mod textile;
 
 use proc_macro2::{Span, TokenStream};
 use std::{
-    fmt, fs,
+    env, fmt, fs,
     io::{self, BufRead},
     path::PathBuf,
 };
@@ -237,8 +237,8 @@ where
 }
 
 fn open(path: &str) -> io::Result<fs::File> {
-    let manifest_dir: PathBuf = option_env!("CARGO_MANIFEST_DIR")
-        .ok_or_else(|| io::Error::other("no manifest directory"))?
+    let manifest_dir: PathBuf = env::var("CARGO_MANIFEST_DIR")
+        .map_err(|_| io::Error::other("no manifest directory"))?
         .into();
     let path = manifest_dir.join(path);
     fs::File::open(path)