diff --git a/fdroidserver/btlog.py b/fdroidserver/btlog.py
index 9c82eea2..452addca 100755
--- a/fdroidserver/btlog.py
+++ b/fdroidserver/btlog.py
@@ -35,12 +35,12 @@ import json
 import logging
 import requests
 import shutil
-import sys
 import tempfile
 import xml.dom.minidom
 import zipfile
 from argparse import ArgumentParser
 
+from .exception import FDroidException
 from . import common
 from . import server
 
@@ -166,8 +166,8 @@ def main():
         logging.getLogger("urllib3").setLevel(logging.WARNING)
 
     if not os.path.exists(options.git_repo):
-        logging.error('"' + options.git_repo + '/" does not exist! Create it, or use --git-repo')
-        sys.exit(1)
+        raise FDroidException(
+            '"%s" does not exist! Create it, or use --git-repo' % options.git_repo)
 
     session = requests.Session()
 
diff --git a/fdroidserver/build.py b/fdroidserver/build.py
index bf790970..755f5764 100644
--- a/fdroidserver/build.py
+++ b/fdroidserver/build.py
@@ -37,7 +37,8 @@ from . import common
 from . import net
 from . import metadata
 from . import scanner
-from .common import FDroidException, BuildException, VCSException, FDroidPopen, SdkToolsPopen
+from .common import FDroidPopen, SdkToolsPopen
+from .exception import FDroidException, BuildException, VCSException
 
 try:
     import paramiko
@@ -582,10 +583,10 @@ def build_local(app, build, vcs, build_dir, output_dir, log_dir, srclib_dir, ext
                 if k.endswith("_orig"):
                     continue
                 logging.critical("  %s: %s" % (k, v))
-            sys.exit(3)
+            raise FDroidException()
         elif not os.path.isdir(ndk_path):
             logging.critical("Android NDK '%s' is not a directory!" % ndk_path)
-            sys.exit(3)
+            raise FDroidException()
 
     common.set_FDroidPopen_env(build)
 
@@ -1256,7 +1257,8 @@ def main():
                         try:
                             net.download_file(url, local_filename=of)
                         except requests.exceptions.HTTPError as e:
-                            raise FDroidException('downloading Binaries from %s failed' % url) from e
+                            raise FDroidException(
+                                'Downloading Binaries from %s failed. %s' % (url, e))
 
                         # Now we check weather the build can be verified to
                         # match the supplied binary or not. Should the
diff --git a/fdroidserver/checkupdates.py b/fdroidserver/checkupdates.py
index 663688b2..cc884505 100644
--- a/fdroidserver/checkupdates.py
+++ b/fdroidserver/checkupdates.py
@@ -17,7 +17,6 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import sys
 import os
 import re
 import urllib.request
@@ -33,8 +32,7 @@ import copy
 
 from . import common
 from . import metadata
-from .common import VCSException, FDroidException
-from .metadata import MetaDataException
+from .exception import VCSException, FDroidException, MetaDataException
 
 
 # Check for a new version by looking at a document retrieved via HTTP.
@@ -498,8 +496,7 @@ def checkupdates_app(app, first=True):
                 gitcmd.extend(['--author', config['auto_author']])
             gitcmd.extend(["--", metadatapath])
             if subprocess.call(gitcmd) != 0:
-                logging.error("Git commit failed")
-                sys.exit(1)
+                raise FDroidException("Git commit failed")
 
 
 config = None
diff --git a/fdroidserver/common.py b/fdroidserver/common.py
index cc1df84e..0ede37a6 100644
--- a/fdroidserver/common.py
+++ b/fdroidserver/common.py
@@ -49,6 +49,7 @@ from pyasn1.error import PyAsn1Error
 from distutils.util import strtobool
 
 import fdroidserver.metadata
+from fdroidserver.exception import FDroidException, VCSException, BuildException
 from .asynchronousfilereader import AsynchronousFileReader
 
 
@@ -234,8 +235,7 @@ def read_config(opts, config_file='config.py'):
             code = compile(f.read(), config_file, 'exec')
             exec(code, None, config)
     elif len(get_local_metadata_files()) == 0:
-        logging.critical("Missing config file - is this a repo directory?")
-        sys.exit(2)
+        raise FDroidException("Missing config file - is this a repo directory?")
 
     for k in ('mirrors', 'install_list', 'uninstall_list', 'serverwebroot', 'servergitroot'):
         if k in config:
@@ -374,13 +374,12 @@ def test_sdk_exists(thisconfig):
 
 def ensure_build_tools_exists(thisconfig):
     if not test_sdk_exists(thisconfig):
-        sys.exit(3)
+        raise FDroidException("Android SDK not found.")
     build_tools = os.path.join(thisconfig['sdk_path'], 'build-tools')
     versioned_build_tools = os.path.join(build_tools, thisconfig['build_tools'])
     if not os.path.isdir(versioned_build_tools):
-        logging.critical('Android Build Tools path "'
-                         + versioned_build_tools + '" does not exist!')
-        sys.exit(3)
+        raise FDroidException(
+            'Android Build Tools path "' + versioned_build_tools + '" does not exist!')
 
 
 def get_local_metadata_files():
@@ -1243,39 +1242,6 @@ def is_valid_package_name(name):
     return re.match("[A-Za-z_][A-Za-z_0-9.]+$", name)
 
 
-class FDroidException(Exception):
-
-    def __init__(self, value, detail=None):
-        self.value = value
-        self.detail = detail
-
-    def shortened_detail(self):
-        if len(self.detail) < 16000:
-            return self.detail
-        return '[...]\n' + self.detail[-16000:]
-
-    def get_wikitext(self):
-        ret = repr(self.value) + "\n"
-        if self.detail:
-            ret += "=detail=\n"
-            ret += "<pre>\n" + self.shortened_detail() + "</pre>\n"
-        return ret
-
-    def __str__(self):
-        ret = self.value
-        if self.detail:
-            ret += "\n==== detail begin ====\n%s\n==== detail end ====" % self.detail.strip()
-        return ret
-
-
-class VCSException(FDroidException):
-    pass
-
-
-class BuildException(FDroidException):
-    pass
-
-
 # Get the specified source library.
 # Returns the path to it. Normally this is the path to be used when referencing
 # it, which may be a subdirectory of the actual project. If you want the base
@@ -1696,8 +1662,7 @@ def get_apk_debuggable_aapt(apkfile):
     p = SdkToolsPopen(['aapt', 'dump', 'xmltree', apkfile, 'AndroidManifest.xml'],
                       output=False)
     if p.returncode != 0:
-        logging.critical("Failed to get apk manifest information")
-        sys.exit(1)
+        raise FDroidException("Failed to get apk manifest information")
     for line in p.output.splitlines():
         if 'android:debuggable' in line and not line.endswith('0x0'):
             return True
@@ -1708,8 +1673,7 @@ def get_apk_debuggable_androguard(apkfile):
     try:
         from androguard.core.bytecodes.apk import APK
     except ImportError:
-        logging.critical("androguard library is not installed and aapt not present")
-        sys.exit(1)
+        raise FDroidException("androguard library is not installed and aapt not present")
 
     apkobject = APK(apkfile)
     if apkobject.is_valid_APK():
@@ -1745,8 +1709,7 @@ def SdkToolsPopen(commands, cwd=None, output=True):
         config[cmd] = find_sdk_tools_cmd(commands[0])
     abscmd = config[cmd]
     if abscmd is None:
-        logging.critical("Could not find '%s' on your system" % cmd)
-        sys.exit(1)
+        raise FDroidException("Could not find '%s' on your system" % cmd)
     if cmd == 'aapt':
         test_aapt_version(config['aapt'])
     return FDroidPopen([abscmd] + commands[1:],
diff --git a/fdroidserver/exception.py b/fdroidserver/exception.py
new file mode 100644
index 00000000..61fa68bd
--- /dev/null
+++ b/fdroidserver/exception.py
@@ -0,0 +1,44 @@
+class FDroidException(Exception):
+
+    def __init__(self, value=None, detail=None):
+        self.value = value
+        self.detail = detail
+
+    def shortened_detail(self):
+        if len(self.detail) < 16000:
+            return self.detail
+        return '[...]\n' + self.detail[-16000:]
+
+    def get_wikitext(self):
+        ret = repr(self.value) + "\n"
+        if self.detail:
+            ret += "=detail=\n"
+            ret += "<pre>\n" + self.shortened_detail() + "</pre>\n"
+        return ret
+
+    def __str__(self):
+        ret = self.value
+        if self.detail:
+            ret += "\n==== detail begin ====\n%s\n==== detail end ====" % self.detail.strip()
+        return ret
+
+
+class MetaDataException(Exception):
+
+    def __init__(self, value):
+        self.value = value
+
+    def __str__(self):
+        return self.value
+
+
+class VCSException(FDroidException):
+    pass
+
+
+class BuildException(FDroidException):
+    pass
+
+
+class VerificationException(FDroidException):
+    pass
diff --git a/fdroidserver/gpgsign.py b/fdroidserver/gpgsign.py
index 4c9cf6bb..159ddf40 100644
--- a/fdroidserver/gpgsign.py
+++ b/fdroidserver/gpgsign.py
@@ -16,7 +16,6 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import sys
 import os
 import glob
 from argparse import ArgumentParser
@@ -24,6 +23,7 @@ import logging
 
 from . import common
 from .common import FDroidPopen
+from .exception import FDroidException
 
 config = None
 options = None
@@ -46,8 +46,7 @@ def main():
 
     for output_dir in repodirs:
         if not os.path.isdir(output_dir):
-            logging.error("Missing output directory '" + output_dir + "'")
-            sys.exit(1)
+            raise FDroidException("Missing output directory '" + output_dir + "'")
 
         # Process any apks that are waiting to be signed...
         for f in sorted(glob.glob(os.path.join(output_dir, '*.*'))):
@@ -70,8 +69,7 @@ def main():
                 gpgargs.append(os.path.join(output_dir, filename))
                 p = FDroidPopen(gpgargs)
                 if p.returncode != 0:
-                    logging.error("Signing failed.")
-                    sys.exit(1)
+                    raise FDroidException("Signing failed.")
 
                 logging.info('Signed ' + filename)
 
diff --git a/fdroidserver/import.py b/fdroidserver/import.py
index 8f11fe23..d0db34a4 100644
--- a/fdroidserver/import.py
+++ b/fdroidserver/import.py
@@ -18,7 +18,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import binascii
-import sys
 import os
 import shutil
 import urllib.request
@@ -28,6 +27,7 @@ import logging
 
 from . import common
 from . import metadata
+from .exception import FDroidException
 
 
 # Get the repo type and address from the given web page. The page is scanned
@@ -123,8 +123,7 @@ def get_metadata_from_url(app, url):
         # Figure out the repo type and adddress...
         repotype, repo = getrepofrompage(app.SourceCode)
         if not repotype:
-            logging.error("Unable to determine vcs type. " + repo)
-            sys.exit(1)
+            raise FDroidException("Unable to determine vcs type. " + repo)
     elif url.startswith('https://') and url.endswith('.git'):
         projecttype = 'git'
         repo = url
@@ -132,10 +131,10 @@ def get_metadata_from_url(app, url):
         app.SourceCode = ""
         app.WebSite = ""
     if not projecttype:
-        logging.error("Unable to determine the project type.")
-        logging.error("The URL you supplied was not in one of the supported formats. Please consult")
-        logging.error("the manual for a list of supported formats, and supply one of those.")
-        sys.exit(1)
+        raise FDroidException("Unable to determine the project type. " +
+                              "The URL you supplied was not in one of the supported formats. " +
+                              "Please consult the manual for a list of supported formats, " +
+                              "and supply one of those.")
 
     # Ensure we have a sensible-looking repo address at this point. If not, we
     # might have got a page format we weren't expecting. (Note that we
@@ -144,8 +143,7 @@ def get_metadata_from_url(app, url):
         not repo.startswith('https://') and
         not repo.startswith('git://'))) or
             ' ' in repo):
-        logging.error("Repo address '{0}' does not seem to be valid".format(repo))
-        sys.exit(1)
+        raise FDroidException("Repo address '{0}' does not seem to be valid".format(repo))
 
     # Get a copy of the source so we can extract some info...
     logging.info('Getting source from ' + repotype + ' repo at ' + repo)
@@ -205,8 +203,7 @@ def main():
 
     local_metadata_files = common.get_local_metadata_files()
     if local_metadata_files != []:
-        logging.error("This repo already has local metadata: %s" % local_metadata_files[0])
-        sys.exit(1)
+        raise FDroidException("This repo already has local metadata: %s" % local_metadata_files[0])
 
     if options.url is None and os.path.isdir('.git'):
         app.AutoName = os.path.basename(os.getcwd())
@@ -236,8 +233,7 @@ def main():
         build.disable = 'Generated by import.py - check/set version fields and commit id'
         write_local_file = False
     else:
-        logging.error("Specify project url.")
-        sys.exit(1)
+        raise FDroidException("Specify project url.")
 
     # Extract some information...
     paths = common.manifest_paths(root_dir, [])
@@ -245,8 +241,7 @@ def main():
 
         versionName, versionCode, package = common.parse_androidmanifests(paths, app)
         if not package:
-            logging.error("Couldn't find package ID")
-            sys.exit(1)
+            raise FDroidException("Couldn't find package ID")
         if not versionName:
             logging.warn("Couldn't find latest version name")
         if not versionCode:
@@ -262,13 +257,11 @@ def main():
             versionName = bconfig.get('app', 'version')
             versionCode = None
         else:
-            logging.error("No android or kivy project could be found. Specify --subdir?")
-            sys.exit(1)
+            raise FDroidException("No android or kivy project could be found. Specify --subdir?")
 
     # Make sure it's actually new...
     if package in apps:
-        logging.error("Package " + package + " already exists")
-        sys.exit(1)
+        raise FDroidException("Package " + package + " already exists")
 
     # Create a build line...
     build.versionName = versionName or '?'
diff --git a/fdroidserver/index.py b/fdroidserver/index.py
index 6eda4a53..f7162092 100644
--- a/fdroidserver/index.py
+++ b/fdroidserver/index.py
@@ -27,7 +27,6 @@ import logging
 import os
 import re
 import shutil
-import sys
 import tempfile
 import urllib.parse
 import zipfile
@@ -37,7 +36,7 @@ from xml.dom.minidom import Document
 
 from fdroidserver import metadata, signindex, common, net
 from fdroidserver.common import FDroidPopen, FDroidPopenBytes
-from fdroidserver.metadata import MetaDataException
+from fdroidserver.exception import FDroidException, VerificationException, MetaDataException
 
 
 def make(apps, sortedids, apks, repodir, archive):
@@ -77,9 +76,8 @@ def make(apps, sortedids, apks, repodir, archive):
             nosigningkey = True
             logging.critical("'" + common.config['keystore'] + "' does not exist!")
         if nosigningkey:
-            logging.warning("`fdroid update` requires a signing key, you can create one using:")
-            logging.warning("\tfdroid update --create-key")
-            sys.exit(1)
+            raise FDroidException("`fdroid update` requires a signing key, " +
+                                  "you can create one using: fdroid update --create-key")
 
     repodict = collections.OrderedDict()
     repodict['timestamp'] = datetime.utcnow()
@@ -118,7 +116,7 @@ def make(apps, sortedids, apks, repodir, archive):
         if mirror is not None:
             mirrors.append(mirror + '/')
     if mirrorcheckfailed:
-        sys.exit(1)
+        raise FDroidException("Malformed repository mirrors.")
     if mirrors:
         repodict['mirrors'] = mirrors
 
@@ -364,9 +362,8 @@ def make_v0(apps, apks, repodir, repodict, requestsdict):
         # Check for duplicates - they will make the client unhappy...
         for i in range(len(apklist) - 1):
             if apklist[i]['versionCode'] == apklist[i + 1]['versionCode']:
-                logging.critical("duplicate versions: '%s' - '%s'" % (
+                raise FDroidException("duplicate versions: '%s' - '%s'" % (
                     apklist[i]['apkName'], apklist[i + 1]['apkName']))
-                sys.exit(1)
 
         current_version_code = 0
         current_version_file = None
@@ -475,8 +472,7 @@ def make_v0(apps, apks, repodir, repodict, requestsdict):
         jar_output = 'index_unsigned.jar' if common.options.nosign else 'index.jar'
         p = FDroidPopen(['jar', 'cf', jar_output, 'index.xml'], cwd=repodir)
         if p.returncode != 0:
-            logging.critical("Failed to create {0}".format(jar_output))
-            sys.exit(1)
+            raise FDroidException("Failed to create {0}".format(jar_output))
 
         # Sign the index...
         signed = os.path.join(repodir, 'index.jar')
@@ -513,8 +509,7 @@ def extract_pubkey():
             msg = "Failed to get repo pubkey!"
             if common.config['keystore'] == 'NONE':
                 msg += ' Is your crypto smartcard plugged in?'
-            logging.critical(msg)
-            sys.exit(1)
+            raise FDroidException(msg)
         pubkey = p.output
     repo_pubkey_fingerprint = common.get_cert_fingerprint(pubkey)
     return hexlify(pubkey), repo_pubkey_fingerprint
@@ -558,10 +553,6 @@ def get_mirror_service_url(url):
     return '/'.join(segments)
 
 
-class VerificationException(Exception):
-    pass
-
-
 def download_repo_index(url_str, etag=None, verify_fingerprint=True):
     """
     Downloads the repository index from the given :param url_str
diff --git a/fdroidserver/init.py b/fdroidserver/init.py
index f29b2d53..e6f400cb 100644
--- a/fdroidserver/init.py
+++ b/fdroidserver/init.py
@@ -28,6 +28,7 @@ from argparse import ArgumentParser
 import logging
 
 from . import common
+from .exception import FDroidException
 
 config = {}
 options = None
@@ -117,7 +118,7 @@ def main():
                 if common.test_sdk_exists(test_config):
                     break
     if not common.test_sdk_exists(test_config):
-        sys.exit(3)
+        raise FDroidException("Android SDK not found.")
 
     if not os.path.exists('config.py'):
         # 'metadata' and 'tmp' are created in fdroid
@@ -135,7 +136,7 @@ def main():
     else:
         logging.warn('Looks like this is already an F-Droid repo, cowardly refusing to overwrite it...')
         logging.info('Try running `fdroid init` in an empty directory.')
-        sys.exit()
+        raise FDroidException('Repository already exists.')
 
     if 'aapt' not in test_config or not os.path.isfile(test_config['aapt']):
         # try to find a working aapt, in all the recent possible paths
diff --git a/fdroidserver/install.py b/fdroidserver/install.py
index 394f16de..9f126428 100644
--- a/fdroidserver/install.py
+++ b/fdroidserver/install.py
@@ -24,7 +24,8 @@ from argparse import ArgumentParser
 import logging
 
 from . import common
-from .common import SdkToolsPopen, FDroidException
+from .common import SdkToolsPopen
+from .exception import FDroidException
 
 options = None
 config = None
diff --git a/fdroidserver/metadata.py b/fdroidserver/metadata.py
index 301a2de0..9d18c4a3 100644
--- a/fdroidserver/metadata.py
+++ b/fdroidserver/metadata.py
@@ -36,20 +36,12 @@ except ImportError:
     YamlLoader = Loader
 
 import fdroidserver.common
+from fdroidserver.exception import MetaDataException
 
 srclibs = None
 warnings_action = None
 
 
-class MetaDataException(Exception):
-
-    def __init__(self, value):
-        self.value = value
-
-    def __str__(self):
-        return self.value
-
-
 def warn_or_exception(value):
     '''output warning or Exception depending on -W'''
     if warnings_action == 'ignore':
diff --git a/fdroidserver/publish.py b/fdroidserver/publish.py
index 622de59c..4d92ebdd 100644
--- a/fdroidserver/publish.py
+++ b/fdroidserver/publish.py
@@ -27,7 +27,8 @@ import logging
 
 from . import common
 from . import metadata
-from .common import FDroidPopen, SdkToolsPopen, BuildException
+from .common import FDroidPopen, SdkToolsPopen
+from .exception import BuildException
 
 config = None
 options = None
diff --git a/fdroidserver/scanner.py b/fdroidserver/scanner.py
index 018a64e6..363f8c8a 100644
--- a/fdroidserver/scanner.py
+++ b/fdroidserver/scanner.py
@@ -24,7 +24,7 @@ import logging
 
 from . import common
 from . import metadata
-from .common import BuildException, VCSException
+from .exception import BuildException, VCSException
 
 config = None
 options = None
diff --git a/fdroidserver/server.py b/fdroidserver/server.py
index d78f6a8a..7ca6009a 100644
--- a/fdroidserver/server.py
+++ b/fdroidserver/server.py
@@ -30,6 +30,7 @@ import logging
 import shutil
 
 from . import common
+from .exception import FDroidException
 
 config = None
 options = None
@@ -97,7 +98,7 @@ def update_awsbucket_s3cmd(repo_section):
                         '--exclude', indexjar,
                         '--exclude', indexv1jar,
                         repo_section, s3url]) != 0:
-        sys.exit(1)
+        raise FDroidException()
     logging.debug('s3cmd sync all files in ' + repo_section + ' to ' + s3url)
     if subprocess.call(s3cmdargs +
                        ['--no-check-md5',
@@ -105,7 +106,7 @@ def update_awsbucket_s3cmd(repo_section):
                         '--exclude', indexjar,
                         '--exclude', indexv1jar,
                         repo_section, s3url]) != 0:
-        sys.exit(1)
+        raise FDroidException()
 
     logging.debug('s3cmd sync indexes ' + repo_section + ' to ' + s3url + ' and delete')
     s3cmdargs.append('--delete-removed')
@@ -115,7 +116,7 @@ def update_awsbucket_s3cmd(repo_section):
     else:
         s3cmdargs.append('--check-md5')
     if subprocess.call(s3cmdargs + [repo_section, s3url]) != 0:
-        sys.exit(1)
+        raise FDroidException()
 
 
 def update_awsbucket_libcloud(repo_section):
@@ -135,8 +136,8 @@ def update_awsbucket_libcloud(repo_section):
     from libcloud.storage.providers import get_driver
 
     if not config.get('awsaccesskeyid') or not config.get('awssecretkey'):
-        logging.error('To use awsbucket, you must set awssecretkey and awsaccesskeyid in config.py!')
-        sys.exit(1)
+        raise FDroidException(
+            'To use awsbucket, you must set awssecretkey and awsaccesskeyid in config.py!')
     awsbucket = config['awsbucket']
 
     cls = get_driver(Provider.S3)
@@ -234,9 +235,9 @@ def update_serverwebroot(serverwebroot, repo_section):
                        ['--exclude', indexxml, '--exclude', indexjar,
                         '--exclude', indexv1jar,
                         repo_section, serverwebroot]) != 0:
-        sys.exit(1)
+        raise FDroidException()
     if subprocess.call(rsyncargs + [repo_section, serverwebroot]) != 0:
-        sys.exit(1)
+        raise FDroidException()
     # upload "current version" symlinks if requested
     if config['make_current_version_link'] and repo_section == 'repo':
         links_to_upload = []
@@ -246,7 +247,7 @@ def update_serverwebroot(serverwebroot, repo_section):
                 links_to_upload.append(f)
         if len(links_to_upload) > 0:
             if subprocess.call(rsyncargs + links_to_upload + [serverwebroot]) != 0:
-                sys.exit(1)
+                raise FDroidException()
 
 
 def _local_sync(fromdir, todir):
@@ -262,7 +263,7 @@ def _local_sync(fromdir, todir):
         rsyncargs += ['--quiet']
     logging.debug(' '.join(rsyncargs + [fromdir, todir]))
     if subprocess.call(rsyncargs + [fromdir, todir]) != 0:
-        sys.exit(1)
+        raise FDroidException()
 
 
 def sync_from_localcopy(repo_section, local_copy_dir):
diff --git a/fdroidserver/signindex.py b/fdroidserver/signindex.py
index 58c7e91f..6b5dd983 100644
--- a/fdroidserver/signindex.py
+++ b/fdroidserver/signindex.py
@@ -16,13 +16,13 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import sys
 import os
 import zipfile
 from argparse import ArgumentParser
 import logging
 
 from . import common
+from .exception import FDroidException
 
 config = None
 options = None
@@ -53,8 +53,7 @@ def sign_jar(jar):
     }
     p = common.FDroidPopen(args, envs=env_vars)
     if p.returncode != 0:
-        logging.critical("Failed to sign %s!" % jar)
-        sys.exit(1)
+        raise FDroidException("Failed to sign %s!" % jar)
 
 
 def sign_index_v1(repodir, json_name):
@@ -87,8 +86,8 @@ def main():
     config = common.read_config(options)
 
     if 'jarsigner' not in config:
-        logging.critical('Java jarsigner not found! Install in standard location or set java_paths!')
-        sys.exit(1)
+        raise FDroidException(
+            'Java jarsigner not found! Install in standard location or set java_paths!')
 
     repodirs = ['repo']
     if config['archive_older'] != 0:
@@ -97,8 +96,7 @@ def main():
     signed = 0
     for output_dir in repodirs:
         if not os.path.isdir(output_dir):
-            logging.error("Missing output directory '" + output_dir + "'")
-            sys.exit(1)
+            raise FDroidException("Missing output directory '" + output_dir + "'")
 
         unsigned = os.path.join(output_dir, 'index_unsigned.jar')
         if os.path.exists(unsigned):
diff --git a/fdroidserver/update.py b/fdroidserver/update.py
index 71277c3e..273b5f0d 100644
--- a/fdroidserver/update.py
+++ b/fdroidserver/update.py
@@ -41,7 +41,8 @@ from . import btlog
 from . import common
 from . import index
 from . import metadata
-from .common import BuildException, SdkToolsPopen
+from .common import SdkToolsPopen
+from .exception import BuildException, FDroidException
 
 METADATA_VERSION = 18
 
@@ -820,8 +821,7 @@ def scan_repo_files(apkcache, repodir, knownapks, use_date_from_file=False):
             continue
         stat = os.stat(filename)
         if stat.st_size == 0:
-            logging.error(filename + ' is zero size!')
-            sys.exit(1)
+            raise FDroidException(filename + ' is zero size!')
 
         shasum = sha256sum(filename)
         usecache = False
@@ -897,7 +897,7 @@ def scan_apk_aapt(apk, apkfile):
                 logging.error("Could not find {0} to remove it".format(apkfile))
         else:
             logging.error("Failed to get apk information, skipping " + apkfile)
-        raise BuildException("Invaild APK")
+        raise BuildException("Invalid APK")
     for line in p.output.splitlines():
         if line.startswith("package:"):
             try:
@@ -905,9 +905,7 @@ def scan_apk_aapt(apk, apkfile):
                 apk['versionCode'] = int(re.match(APK_VERCODE_PAT, line).group(1))
                 apk['versionName'] = re.match(APK_VERNAME_PAT, line).group(1)
             except Exception as e:
-                logging.error("Package matching failed: " + str(e))
-                logging.info("Line was: " + line)
-                sys.exit(1)
+                raise FDroidException("Package matching failed: " + str(e) + "\nLine was: " + line)
         elif line.startswith("application:"):
             apk['name'] = re.match(APK_LABEL_PAT, line).group(1)
             # Keep path to non-dpi icon in case we need it
@@ -1000,11 +998,10 @@ def scan_apk_androguard(apk, apkfile):
                 logging.error("Failed to get apk information, skipping " + apkfile)
             raise BuildException("Invaild APK")
     except ImportError:
-        logging.critical("androguard library is not installed and aapt not present")
-        sys.exit(1)
+        raise FDroidException("androguard library is not installed and aapt not present")
     except FileNotFoundError:
         logging.error("Could not open apk file for analysis")
-        raise BuildException("Invaild APK")
+        raise BuildException("Invalid APK")
 
     apk['packageName'] = apkobject.get_package()
     apk['versionCode'] = int(apkobject.get_androidversion_code())
@@ -1508,8 +1505,7 @@ def main():
     config = common.read_config(options)
 
     if not ('jarsigner' in config and 'keytool' in config):
-        logging.critical('Java JDK not found! Install in standard location or set java_paths!')
-        sys.exit(1)
+        raise FDroidException('Java JDK not found! Install in standard location or set java_paths!')
 
     repodirs = ['repo']
     if config['archive_older'] != 0:
diff --git a/fdroidserver/verify.py b/fdroidserver/verify.py
index 8539775f..966c3874 100644
--- a/fdroidserver/verify.py
+++ b/fdroidserver/verify.py
@@ -25,7 +25,7 @@ import logging
 
 from . import common
 from . import net
-from .common import FDroidException
+from .exception import FDroidException
 
 options = None
 config = None
@@ -80,7 +80,7 @@ def main():
             try:
                 net.download_file(url, dldir=tmp_dir)
             except requests.exceptions.HTTPError as e:
-                raise FDroidException('downloading %s failed', url) from e
+                raise FDroidException('Downloading %s failed. %s', (url, e))
 
             compare_result = common.verify_apks(
                 remoteapk,