ignore UniqueViolation errors in inserts

src/database.rs

@@ -8,6 +8,7 @@ use diesel::debug_query;
 use diesel::expression::operators::{And, Or};
 use diesel::prelude::*;
 use diesel::r2d2::{self, ConnectionManager};
+use diesel::result::{DatabaseErrorKind, Error};
 use diesel::sql_types::Bool;
 use diesel::sqlite::{Sqlite, SqliteConnection};
 use lexpr::value::Value::Symbol;
@@ -590,9 +591,16 @@ pub fn insert_entry<C: Connection<Backend = Sqlite>>(
 
     let entry = Entry::try_from(&insert_entry)?;
 
-    diesel::insert_into(data::table)
+    let result = diesel::insert_into(data::table)
         .values(insert_entry)
-        .execute(connection)?;
+        .execute(connection);
+
+    if let Some(error) = result.err() {
+        match error {
+            Error::DatabaseError(DatabaseErrorKind::UniqueViolation, _) => {}
+            _ => return Err(anyhow!(error)),
+        }
+    }
 
     Ok(Address::Hash(entry.hash()?))
 }