Switch from failure to anyhow.

  - Use the anyhow crate instead of failure to implement the dynamic
    side of our error handling.  anyhow::Error derefs to dyn
    std::error::Error, allowing better interoperability with other
    stdlib-based error handling libraries.

  - Fixes #444.

3 files changed, 8 insertions, 9 deletions

diff --git a/net/Cargo.toml b/net/Cargo.toml
index f817a6b2..86a4404c 100644
--- a/net/Cargo.toml
+++ b/net/Cargo.toml
@@ -24,7 +24,7 @@ maintenance = { status = "actively-developed" }
 sequoia-openpgp = { path = "../openpgp", version = "0.15", default-features = false }
 sequoia-core = { path = "../core", version = "0.15" }
 
-failure = "0.1.2"
+anyhow = "1"
 futures = "0.1"
 http = "0.1.5"
 hyper = "0.12"
diff --git a/net/src/lib.rs b/net/src/lib.rs
index b7ed9cdc..15f6ddb0 100644
--- a/net/src/lib.rs
+++ b/net/src/lib.rs
@@ -38,7 +38,6 @@
 extern crate sequoia_openpgp as openpgp;
 extern crate sequoia_core;
 
-extern crate failure;
 extern crate futures;
 extern crate http;
 extern crate hyper;
@@ -157,7 +156,7 @@ impl KeyServer {
 
     /// Retrieves the key with the given `keyid`.
     pub fn get(&mut self, keyid: &KeyID)
-               -> Box<dyn Future<Item=Cert, Error=failure::Error> + 'static> {
+               -> Box<dyn Future<Item=Cert, Error=anyhow::Error> + 'static> {
         let keyid_want = keyid.clone();
         let uri = self.uri.join(
             &format!("pks/lookup?op=get&options=mr&search=0x{}",
@@ -205,7 +204,7 @@ impl KeyServer {
 
     /// Sends the given key to the server.
     pub fn send(&mut self, key: &Cert)
-                -> Box<dyn Future<Item=(), Error=failure::Error> + 'static> {
+                -> Box<dyn Future<Item=(), Error=anyhow::Error> + 'static> {
         use crate::openpgp::armor::{Writer, Kind};
 
         let uri =
@@ -291,7 +290,7 @@ pub(crate) fn url2uri(uri: Url) -> hyper::Uri {
 }
 
 /// Results for sequoia-net.
-pub type Result<T> = ::std::result::Result<T, failure::Error>;
+pub type Result<T> = ::std::result::Result<T, anyhow::Error>;
 
 #[derive(thiserror::Error, Debug)]
 /// Errors returned from the network routines.
diff --git a/net/src/wkd.rs b/net/src/wkd.rs
index 4c9e0283..526ca14b 100644
--- a/net/src/wkd.rs
+++ b/net/src/wkd.rs
@@ -22,7 +22,7 @@ use std::fmt;
 use std::fs;
 use std::path::{Path, PathBuf};
 
-use failure::ResultExt;
+use anyhow::Context;
 use futures::{future, Future, Stream};
 use hyper::{Uri, Client};
 use hyper_tls::HttpsConnector;
@@ -291,7 +291,7 @@ fn parse_body<S: AsRef<str>>(body: &[u8], email_address: S)
 // XXX: Maybe the direct method should be tried on other errors too.
 // https://mailarchive.ietf.org/arch/msg/openpgp/6TxZc2dQFLKXtS0Hzmrk963EteE
 pub fn get<S: AsRef<str>>(email_address: S)
-                          -> impl Future<Item=Vec<Cert>, Error=failure::Error> {
+                          -> impl Future<Item=Vec<Cert>, Error=anyhow::Error> {
     let email = email_address.as_ref().to_string();
     future::lazy(move || -> Result<_> {
         // First, prepare URIs and client.
@@ -407,14 +407,14 @@ impl KeyRing {
 impl crate::openpgp::serialize::Serialize for KeyRing {}
 
 impl Marshal for KeyRing {
-    fn serialize(&self, o: &mut dyn std::io::Write) -> Result<()> {
+    fn serialize(&self, o: &mut dyn std::io::Write) -> openpgp::Result<()> {
         for cert in self.0.values() {
             cert.serialize(o)?;
         }
         Ok(())
     }
 
-    fn export(&self, o: &mut dyn std::io::Write) -> Result<()> {
+    fn export(&self, o: &mut dyn std::io::Write) -> openpgp::Result<()> {
         for cert in self.0.values() {
             cert.export(o)?;
         }