diff --git a/bananas_cli/cli.py b/bananas_cli/cli.py
index 59da5e7..d66ca41 100644
--- a/bananas_cli/cli.py
+++ b/bananas_cli/cli.py
@@ -1,9 +1,11 @@
 import click
 import logging
 
+from aiohttp.client_exceptions import ClientConnectorError
 from .authentication import authenticate
 from .helpers import task
 from .session import Session
+from .exceptions import Exit
 
 log = logging.getLogger(__name__)
 pass_session = click.make_pass_decorator(Session)
@@ -19,9 +21,10 @@
 @click.option("--tus-url", help="BaNaNaS tus URL. (normally the same as --api-url)", metavar="URL")
 @click.option("--client-id", help="Client-id to use for authentication", default="ape", show_default=True)
 @click.option("--audience", help="Audience to use for authentication", default="github", show_default=False)
+@click.option("--verbose", help="Enable verbose output for errors, showing tracebacks", is_flag=True)
 @click.pass_context
 @task
-async def cli(ctx, api_url, tus_url, client_id, audience):
+async def cli(ctx, api_url, tus_url, client_id, audience, verbose):
     """
     A CLI tool to list, upload, and otherwise modify BaNaNaS content.
 
@@ -40,7 +43,7 @@ async def cli(ctx, api_url, tus_url, client_id, audience):
     if not tus_url:
         tus_url = api_url
 
-    session = Session(api_url, tus_url)
+    session = Session(api_url, tus_url, verbose)
     ctx.obj = session
 
     await session.start()
@@ -49,7 +52,14 @@ async def cli(ctx, api_url, tus_url, client_id, audience):
     if "-h" in os_args or "--help" in os_args:
         return
 
-    await authenticate(session, client_id, audience)
+    try:
+        await authenticate(session, client_id, audience)
+    except (ClientConnectorError, NameError) as e:
+        if verbose:
+            log.exception(e)
+        else:
+            log.error(e)
+        raise Exit
 
 
 @task
diff --git a/bananas_cli/commands/upload.py b/bananas_cli/commands/upload.py
index ba5c292..95a76a6 100644
--- a/bananas_cli/commands/upload.py
+++ b/bananas_cli/commands/upload.py
@@ -28,6 +28,9 @@ def show_validation_errors(data):
 @pass_session
 @task
 async def upload(session, version, name, description, url, license, files):
+    if len(files) == 0:
+        log.error("No files specified for upload")
+        return
     parts = files[0].split("/")[:-1]
     for filename in files:
         check_parts = filename.split("/")
diff --git a/bananas_cli/session.py b/bananas_cli/session.py
index f9a4ed2..10be440 100644
--- a/bananas_cli/session.py
+++ b/bananas_cli/session.py
@@ -13,12 +13,13 @@
 
 
 class Session:
-    def __init__(self, api_url, tus_url):
+    def __init__(self, api_url, tus_url, verbose):
         self.session = None
         self.api_url = f"{api_url}/"
         self.tus_url = f"{tus_url}/"
 
         self._headers = {}
+        self.verbose = verbose
 
     async def start(self):
         self.session = aiohttp.ClientSession()
@@ -64,8 +65,11 @@ def tus_upload(self, upload_token, fullpath, filename):
                 metadata={"filename": filename, "upload-token": upload_token},
             )
             uploader.upload()
-        except TusCommunicationError:
-            log.exception(f"Failed to upload file '{filename}'")
+        except TusCommunicationError as e:
+            if self.verbose:
+                log.exception(f"Failed to upload file '{filename}'")
+            else:
+                log.error(f"Failed to upload file '{filename}': {e}")
             raise Exit
 
     def set_header(self, header, value):