macros: Drop anyhow dependency

It is used in a single place and it is easy to remove, so it doesn't
seem
worth it to keep depending on it.

gtk4-macros/Cargo.toml

@@ -21,7 +21,6 @@ xml_validation = ["quick-xml"]
 blueprint = []
 
 [dependencies]
-anyhow = "1.0"
 quick-xml = {version = "0.31", optional = true}
 proc-macro-crate = "3.0"
 proc-macro2 = "1.0"

gtk4-macros/src/blueprint.rs

@@ -5,7 +5,8 @@ use std::{
     process::{Command, Stdio},
 };
 
-use anyhow::{bail, Result};
+use proc_macro2::Span;
+use syn::{Error, Result};
 
 pub(crate) fn compile_blueprint(blueprint: &[u8]) -> Result<String> {
     let mut compiler = Command::new("blueprint-compiler")
@@ -24,7 +25,7 @@ pub(crate) fn compile_blueprint(blueprint: &[u8]) -> Result<String> {
     compiler.stdout.unwrap().read_to_string(&mut buf)?;
 
     if !buf.starts_with('<') {
-        bail!(buf);
+        return Error::new(Span::call_site(), buf);
     }
 
     Ok(buf)

gtk4-macros/src/lib.rs

@@ -54,11 +54,7 @@ pub fn include_blueprint(input: TokenStream) -> TokenStream {
 
     let template = match std::fs::read_to_string(&path) {
         Ok(content) => blueprint::compile_blueprint(content.as_bytes()).unwrap(),
-        Err(err) => {
-            return Error::new(Span::call_site(), err)
-                .into_compile_error()
-                .into()
-        }
+        Err(err) => return err.into_compile_error().into(),
     };
 
     quote!({