#482 File recorders PermissionDenied errors are not verbose

[Zbigniew Reszela]

File recorders like: Spec or Nexus do not indicate the PermissionDenied errors verbosely enough.

How to reproduce it:

1. Create an empty file without write permissions to the user running the MacroServer (as root: touch /tmp/rootfile.dat or touch /tmp/rootfile.h5
2. Run a scan.

Spec recorder reports it in the following way:

Door_zreszela_1 [62]: %ascan mot01 0 1 1 0.1
Operation will be saved in /tmp/rootfile.dat (Spec)
Scan #843 started at Mon May 23 15:12:37 2016. It will take at least 0:00:00.573205
Moving to start positions...
 #Pt No    mot01      ct01       dt   
An error occurred while running Macro 'ascan(mot01, 0.0, 1.0, 1, 0.1) -> 05886ada-20e8-11e6-af96-f8b156a48f79':
13

Nexus is a little bit more verbose:

Door_zreszela_1 [68]: %ascan mot01 0 1 1 0.1
Operation will be saved in /tmp/rootfile.h5 (w5)
Scan #846 started at Mon May 23 15:15:21 2016. It will take at least 0:00:00.573205
Moving to start positions...
 #Pt No    mot01      ct01       dt   
An error occurred while running Macro 'ascan(mot01, 0.0, 1.0, 1, 0.1) -> 6740d1a4-20e8-11e6-af96-f8b156a48f79':
Could not open /tmp/rootfile.h5

[Carlos Falcon]

A patch has been sent to the list.

[Zbigniew Reszela]

Another solution was proposed in reply to Carlos's patch.

[Zbigniew Reszela]

Aplied the latest patch to the develop branch.