More and better context

src/fe/mod.rs

@@ -82,16 +82,16 @@ impl AsRawFd for FeDevice {
 
 #[macro_export]
 macro_rules! get_dtv_properties {
-    ( $device:expr, $( $property:ident ),+ ) => { (|| -> anyhow::Result<_> {
+    ( $device:expr, $( $property:ident ),+ ) => { (|| -> ::anyhow::Result<_> {
         let mut input = [ $( $property(DtvPropertyRequest::default()), )* ];
-        $device.get_properties(&mut input)?;
+        $device.get_properties(&mut input).context("Error fetching properties")?;
         let mut iterator = input.iter();
         Ok((
             $(
                 match iterator.next() {
                     Some($property(d)) => d.get(),
-                    _ => ::anyhow::Result::Err(anyhow!("Error unpacking")),
-                }?,
+                    _ => ::anyhow::Result::Err(anyhow!("Missing value")),
+                }.with_context(|| format!("Error unpacking {}", stringify!($property)))?,
             )*
         ))
     })()}

src/fe/status.rs

@@ -2,7 +2,7 @@ use crate::get_dtv_properties;
 
 use {
     super::{sys::*, FeDevice},
-    anyhow::Result,
+    anyhow::{Context, Result},
     std::fmt,
 };
 

src/fe/sys.rs

@@ -868,7 +868,7 @@ macro_rules! dtv_property {
 #[macro_export]
 macro_rules! dtv_property_parse {
     ( $property:ident($data:expr)) => {
-        $property(DtvPropertyRequest::new($data.parse().context(format!("Invalid {}: {}", stringify!($property), $data))?))
+        $property(DtvPropertyRequest::new($data.parse().with_context(||format!("Invalid {}: {}", stringify!($property), $data))?))
     };
 }