sq: Improve error message for --session-key.

  - Add context to error if parsing the	`--session key` argument to `sq
    packet dump` failed.

1 files changed, 5 insertions, 1 deletions

diff --git a/sq/src/sq.rs b/sq/src/sq.rs
index 87a476f6..4305f164 100644
--- a/sq/src/sq.rs
+++ b/sq/src/sq.rs
@@ -662,7 +662,11 @@ fn main() -> Result<()> {
                     config.create_or_stdout_unsafe(m.value_of("output"))?;
                 let session_key: Option<openpgp::crypto::SessionKey> =
                     if let Some(sk) = m.value_of("session-key") {
-                        Some(hex::decode_pretty(sk)?.into())
+                        let dsk = hex::decode_pretty(sk).with_context(|| format!(
+                            "Bad value passed to --session-key: {:?}",
+                            sk
+                        ))?;
+                        Some(dsk.into())
                     } else {
                         None
                     };