hw: check_libraries_available now gets version of incompatible libs

previously we would return early and the user would
just see "missing libraries"

electrum/plugins/coldcard/coldcard.py

@@ -17,6 +17,7 @@ from electrum.util import print_error, bfh, bh2u, versiontuple, UserFacingExcept
 from electrum.base_wizard import ScriptTypeNotSupported
 
 from ..hw_wallet import HW_PluginBase
+from ..hw_wallet.plugin import LibraryFoundButUnusable
 
 try:
     import hid
@@ -610,7 +611,7 @@ class ColdcardPlugin(HW_PluginBase):
     def __init__(self, parent, config, name):
         HW_PluginBase.__init__(self, parent, config, name)
 
-        self.libraries_available = self.check_libraries_available() and requirements_ok
+        self.libraries_available = self.check_libraries_available()
         if not self.libraries_available:
             return
 
@@ -620,9 +621,13 @@ class ColdcardPlugin(HW_PluginBase):
     def get_library_version(self):
         import ckcc
         try:
-            return ckcc.__version__
+            version = ckcc.__version__
         except AttributeError:
-            return 'unknown'
+            version = 'unknown'
+        if requirements_ok:
+            return version
+        else:
+            raise LibraryFoundButUnusable(library_version=version)
 
     def detect_simulator(self):
         # if there is a simulator running on this machine,

electrum/plugins/hw_wallet/plugin.py

@@ -86,6 +86,7 @@ class HW_PluginBase(BasePlugin):
 
         Returns 'unknown' if library is found but cannot determine version.
         Raises 'ImportError' if library is not found.
+        Raises 'LibraryFoundButUnusable' if found but there was some problem (includes version num).
         """
         raise NotImplementedError()
 
@@ -94,23 +95,22 @@ class HW_PluginBase(BasePlugin):
             return ".".join(str(i) for i in t)
 
         try:
+            # this might raise ImportError or LibraryFoundButUnusable
             library_version = self.get_library_version()
+            # if no exception so far, we might still raise LibraryFoundButUnusable
+            if (library_version == 'unknown'
+                    or versiontuple(library_version) < self.minimum_library
+                    or hasattr(self, "maximum_library") and versiontuple(library_version) >= self.maximum_library):
+                raise LibraryFoundButUnusable(library_version=library_version)
         except ImportError:
             return False
-        if library_version == 'unknown' or \
-                versiontuple(library_version) < self.minimum_library:
-            self.libraries_available_message = (
-                    _("Library version for '{}' is too old.").format(self.name)
-                    + '\nInstalled: {}, Needed: {}'
-                    .format(library_version, version_str(self.minimum_library)))
-            self.print_stderr(self.libraries_available_message)
-            return False
-        elif hasattr(self, "maximum_library") and \
-                versiontuple(library_version) >= self.maximum_library:
+        except LibraryFoundButUnusable as e:
+            library_version = e.library_version
+            max_version_str = version_str(self.maximum_library) if hasattr(self, "maximum_library") else "inf"
             self.libraries_available_message = (
                     _("Library version for '{}' is incompatible.").format(self.name)
-                    + '\nInstalled: {}, Needed: less than {}'
-                    .format(library_version, version_str(self.maximum_library)))
+                    + '\nInstalled: {}, Needed: {} <= x < {}'
+                    .format(library_version, version_str(self.minimum_library), max_version_str))
             self.print_stderr(self.libraries_available_message)
             return False
 
@@ -155,3 +155,8 @@ def only_hook_if_libraries_available(func):
         if not self.libraries_available: return None
         return func(self, *args, **kwargs)
     return wrapper
+
+
+class LibraryFoundButUnusable(Exception):
+    def __init__(self, library_version='unknown'):
+        self.library_version = library_version

electrum/plugins/trezor/trezor.py

@@ -12,7 +12,8 @@ from electrum.keystore import Hardware_KeyStore, is_xpubkey, parse_xpubkey
 from electrum.base_wizard import ScriptTypeNotSupported, HWD_SETUP_NEW_WALLET
 
 from ..hw_wallet import HW_PluginBase
-from ..hw_wallet.plugin import is_any_tx_output_on_change_branch, trezor_validate_op_return_output_and_get_data
+from ..hw_wallet.plugin import (is_any_tx_output_on_change_branch, trezor_validate_op_return_output_and_get_data,
+                                LibraryFoundButUnusable)
 
 try:
     import trezorlib
@@ -112,12 +113,15 @@ class TrezorPlugin(HW_PluginBase):
         self.device_manager().register_enumerate_func(self.enumerate)
 
     def get_library_version(self):
-        if not TREZORLIB:
-            raise ImportError
+        import trezorlib
         try:
-            return trezorlib.__version__
+            version = trezorlib.__version__
         except Exception:
-            return 'unknown'
+            version = 'unknown'
+        if TREZORLIB:
+            return version
+        else:
+            raise LibraryFoundButUnusable(library_version=version)
 
     def enumerate(self):
         devices = trezorlib.transport.enumerate_devices()