Squashed commit of the following:

    Add op25_python installation file to .gitignore
    Fix SIGSEGV when pulse audio doesn't open properly
    Repair gdb pause option broken by python2/3 changes
    Extra error-checking for cleaner shutdown
    Changes to install script and cmake build environment to automatically
      figure out gnuradio version and python version

CMakeLists.txt

@@ -1,7 +1,85 @@
+########################################################################
+# Project setup
+########################################################################
 cmake_minimum_required(VERSION 2.6)
 project(gr-op25 CXX C)
+enable_testing()
+
+#select the release build type by default to get optimization flags
+if(NOT CMAKE_BUILD_TYPE)
+   set(CMAKE_BUILD_TYPE "Release")
+   message(STATUS "Build type not specified: defaulting to release.")
+endif(NOT CMAKE_BUILD_TYPE)
+set(CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE} CACHE STRING "")
+
+########################################################################
+# Compiler specific setup
+########################################################################
+if(CMAKE_COMPILER_IS_GNUCXX AND NOT WIN32)
+    #http://gcc.gnu.org/wiki/Visibility
+    add_definitions(-fvisibility=hidden)
+endif()
 
+########################################################################
+# Find boost
+########################################################################
+if(UNIX AND EXISTS "/usr/lib64")
+    list(APPEND BOOST_LIBRARYDIR "/usr/lib64") #fedora 64-bit fix
+endif(UNIX AND EXISTS "/usr/lib64")
+set(Boost_ADDITIONAL_VERSIONS
+    "1.35.0" "1.35" "1.36.0" "1.36" "1.37.0" "1.37" "1.38.0" "1.38" "1.39.0" "1.39"
+    "1.40.0" "1.40" "1.41.0" "1.41" "1.42.0" "1.42" "1.43.0" "1.43" "1.44.0" "1.44"
+    "1.45.0" "1.45" "1.46.0" "1.46" "1.47.0" "1.47" "1.48.0" "1.48" "1.49.0" "1.49"
+    "1.50.0" "1.50" "1.51.0" "1.51" "1.52.0" "1.52" "1.53.0" "1.53" "1.54.0" "1.54"
+    "1.55.0" "1.55" "1.56.0" "1.56" "1.57.0" "1.57" "1.58.0" "1.58" "1.59.0" "1.59"
+    "1.60.0" "1.60" "1.61.0" "1.61" "1.62.0" "1.62" "1.63.0" "1.63" "1.64.0" "1.64"
+    "1.65.0" "1.65" "1.66.0" "1.66" "1.67.0" "1.67" "1.68.0" "1.68" "1.69.0" "1.69"
+)
+find_package(Boost "1.35" COMPONENTS filesystem system)
+
+if(NOT Boost_FOUND)
+    message(FATAL_ERROR "Boost required to compile op25")
+endif()
+
+########################################################################
+# Find gnuradio build dependencies
+########################################################################
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/Modules)
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+find_package(CppUnit)
+if(NOT CPPUNIT_FOUND)
+    message(FATAL_ERROR "CppUnit required to compile op25")
+endif()
+set(GR_REQUIRED_COMPONENTS RUNTIME BLOCKS FILTER PMT)
+find_package(GnuradioRuntime)
+find_package(Gnuradio REQUIRED)
+MESSAGE(STATUS "GnuRadio version ${Gnuradio_VERSION}")
+if ("${Gnuradio_VERSION}" VERSION_LESS "2.7.0")
+    MESSAGE(FATAL_ERROR "OP25 Required Gnuradio minimum version 2.7.0")
+elseif ("${Gnuradio_VERSION}" VERSION_LESS "3.8.0")
+    set(OP25_PYTHON_VER 2)
+else()
+    set(OP25_PYTHON_VER 3) 
+endif()
+MESSAGE(STATUS "Configuring for Python ${OP25_PYTHON_VER}")
+
+execute_process(COMMAND python${OP25_PYTHON_VER} -c "
+import os
+import sys
+from distutils import sysconfig
+pfx = '/usr/local'
+m1 = os.path.join('lib', 'python' + sys.version[:3], 'dist-packages')
+m2 = sysconfig.get_python_lib(plat_specific=True, prefix='')
+f1 = os.path.join(pfx, m1)
+f2 = os.path.join(pfx, m2)
+ok2 = f2 in sys.path
+if ok2:
+	print(m2)
+else:
+	print(m1)
+" OUTPUT_VARIABLE OP25_PYTHON_DIR OUTPUT_STRIP_TRAILING_WHITESPACE
+)
+MESSAGE(STATUS "OP25_PYTHON_DIR has been set to \"${OP25_PYTHON_DIR}\".")
 
 add_subdirectory(op25/gr-op25)
 add_subdirectory(op25/gr-op25_repeater)

README-installation

@@ -4,7 +4,8 @@ These high level instructions will lead you through installing op25
 on Debian based Linux systems such as Ubuntu, Linux Mint and similar.
 
 Note 1: op25 is currently tested against gnuradio-3.7/python2 with Ubuntu 16.04
-and gnuradio-3.8/python3 with Ubuntu 20.04.  
+and gnuradio-3.8/python3 with Ubuntu 20.04. Build environment automatically figures
+out which version of gnuradio you have and therefore which version of python to use. 
 
 Note 2: versions of cmake later than 3.10.3 have been known to cause dependency
 issues while building the swig libraries on pyhton2. At the current time if you

cmake/Modules/GrSwig.cmake

@@ -114,7 +114,7 @@ macro(GR_SWIG_MAKE name)
     endif()
 
     #append additional include directories
-    find_package(PythonLibs 2)
+    find_package(PythonLibs ${OP25_PYTHON_VER})
     list(APPEND GR_SWIG_INCLUDE_DIRS ${PYTHON_INCLUDE_PATH}) #deprecated name (now dirs)
     list(APPEND GR_SWIG_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS})
     list(APPEND GR_SWIG_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR})

install.sh

@@ -16,7 +16,6 @@ sudo apt-get update
 GR_VER=$(apt list gnuradio 2>/dev/null | grep -m 1 gnuradio | cut -d' ' -f2 | cut -d'.' -f1,2)
 if [ ${GR_VER} = "3.8" ]; then
     echo "Installing for GNURadio 3.8"
-    cat gr3.8.patch | patch -N -p1 -r -
     sudo sed -i -- 's/^# *deb-src/deb-src/' /etc/apt/sources.list
     sudo apt-get build-dep gnuradio
     sudo apt-get install gnuradio gnuradio-dev gr-osmosdr librtlsdr-dev libuhd-dev  libhackrf-dev libitpp-dev libpcap-dev cmake git swig build-essential pkg-config doxygen python3-numpy python3-waitress python3-requests gnuplot-x11
@@ -30,7 +29,7 @@ else
     sudo apt-get install gnuradio gnuradio-dev gr-osmosdr librtlsdr-dev libuhd-dev  libhackrf-dev libitpp-dev libpcap-dev cmake git swig build-essential pkg-config doxygen python-numpy python-waitress python-requests gnuplot-x11
 
     # Tell op25 to use python2
-    echo "/usr/bin/python" > op25/gr-op25_repeater/apps/op25_python
+    echo "/usr/bin/python2" > op25/gr-op25_repeater/apps/op25_python
 
 fi