(If you find progress and other non-error messages irritating, you can use -q to suppress them)

(You can use the -w option to dump extensions.conf format to extensions.conf.aeldump)
LOG: lev:2 file:pbx_ael.c  line:4090 func: pbx_load_module  Starting AEL load process.
LOG: lev:2 file:pbx_ael.c  line:4097 func: pbx_load_module  AEL load process: calculated config file name './extensions.ael'.
LOG: lev:2 file:pbx_ael.c  line:4105 func: pbx_load_module  AEL load process: parsed config file name './extensions.ael'.
LOG: lev:4 file:pbx_ael.c  line:2250 func: check_context_names  Error: file ./extensions.ael, line 49-62: The context name (incoming) is also declared in file ./extensions.ael, line 62-69! (and neither is marked 'extend')
LOG: lev:3 file:pbx_ael.c  line:2234 func: check_switch_expr  Warning: file ./extensions.ael, line 245-246: A default case was automatically added to the switch.
LOG: lev:3 file:pbx_ael.c  line:2347 func: check_pval_item  Warning: file ./extensions.ael, line 312-312: macro call to non-existent funcA ! Hopefully it is present in extensions.conf! 
LOG: lev:3 file:pbx_ael.c  line:2347 func: check_pval_item  Warning: file ./extensions.ael, line 313-313: macro call to non-existent funcD ! Hopefully it is present in extensions.conf! 
LOG: lev:3 file:pbx_ael.c  line:1287 func: check_goto  Warning: file ./extensions.ael, line 319-319: goto:  no context test5 could be found that matches the goto target!
LOG: lev:4 file:pbx_ael.c  line:4118 func: pbx_load_module  Sorry, but 0 syntax errors and 1 semantic errors were detected. It doesn't make sense to compile.
LOG: lev:4 file:ael2_parse  line:543 func: main  0 contexts, 0 extensions, 0 priorities