Explore shutting down scdaemon when accessing cards via pcsc.

card-functionality/Cargo.toml

@@ -15,4 +15,5 @@ openpgp-card-scdc = { path = "../scdc" }
 sequoia-openpgp = "1.3"
 anyhow = "1"
 thiserror = "1.0"
-env_logger = "0.8"
+env_logger = "0.8"
+log = "0.4"

card-functionality/src/main.rs

@@ -49,6 +49,11 @@ impl TestCard {
     fn open(&self) -> Result<CardApp> {
         match self {
             Self::Pcsc(ident) => {
+                // Attempt to shutdown SCD, if it is running.
+                // Ignore any errors that occur during that shutdown attempt.
+                let res = ScdClient::shutdown_scd(None);
+                log::trace!(" Attempt to shutdown scd: {:?}", res);
+
                 for card in PcscClient::list_cards()? {
                     let card_client = Box::new(card) as CardClientBox;
                     let mut ca = CardApp::new(card_client);