skip library for doc-only

Author: smurfix

.travis.yml

@@ -3,10 +3,11 @@ python:
   - 3.6
 sudo: false
 dist: trusty
-addons:
-  apt:
-    packages:
-    - libgpiod1
+## we need that for actual tests
+#addons:
+#  apt:
+#    packages:
+#    - libgpiod1
 
 env:
 - CHECK_DOCS=1

trio_gpio/libgpiod.py

@@ -297,7 +297,10 @@
 """
 )
 
-lib = ffi.dlopen("libgpiod.so.1")
+try:
+    lib = ffi.dlopen("libgpiod.so.1")
+except OSError:
+    lib = None # may fail if we're only building docs
 
 DIRECTION_INPUT = lib.GPIOD_LINE_REQUEST_DIRECTION_INPUT
 DIRECTION_OUTPUT = lib.GPIOD_LINE_REQUEST_DIRECTION_OUTPUT