added changelog entry and fixed python2.7 compatibility

Author: gfelber

CHANGELOG.md

@@ -71,6 +71,7 @@ The table below shows which release corresponds to each branch, and what date th
 
 ## 4.14.0 (`dev`)
 
+- [#2382][2382] added optional port and gdb_args parameters to gdb.debug()
 - [#2360][2360] Add offline parameter for `search_by_hash` series function
 - [#2356][2356] Add local libc database provider for libcdb
 - [#2374][2374] libcdb.unstrip_libc: debug symbols are fetched only if not present

pwnlib/gdb.py

@@ -348,7 +348,7 @@ def _gdbserver_args(pid=None, path=None, port=0, args=None, which=None, env=None
     elif env is not None:
         gdbserver_args += ['--wrapper', which('env'), '-i'] + env_args + ['--']
 
-    gdbserver_args += [f'localhost:{port}']
+    gdbserver_args += ['localhost:%d' % port]
     gdbserver_args += args
 
     return gdbserver_args