Unable to Create a Virtual Feed


I’m using an EmonPI and my Emoncms software version is 9.9.8.

I have two feeds (A and B) 'Logged to Feed". If I try to create a New Virtual Feed using ‘Source Feed’ and ‘Feed A’, I get the following error message: ERROR: Could not save processlist. Cannot use virtual feed as source.

Am I missing something? (besides a functional brain) :smile: ?



[See Virtual Feed : add values from input - Moderator - RW]


Same problem in fresh install Release emonSD-30Oct18, 9.9.8 version.
Any solution ?


@nchaveiro is the creator of virtual feeds - he might be able to help.

Thanks Robert. Let’s hope @nchaveiro can help. Chaveiro multi tariff code is the best to use in Portugal.

I make some test to try to identify this problem (try to eliminate users problems) and made some clean installs in emonSD-30Oct18 and emonSD-26Oct17 (all updated automatic to 9.9.8 version). Insert some base test inputs and feeds and try to create the virtual. The have the same problem. I can’t use virtual feed.

I verify my old emonSD instalation and made a clean instalation with emonSD-07Nov16 (stay in 9.7.7, because update don’t work) and test again with the same inputs and feeds. I can use the virtual feed again.
Of course, this version is outdated and without update, i think is better not use.

Beside @nchaveiro, can some one help.
I try to update my emoncms local because my base install (emonSD-07Nov16) have SD problems card and can’t generate a backup, so it’s necessary to rebuild all the system, but I verify difficulties to do the same parameters.

Thanks in advance,

Best Regards.

The error you’re getting is due to the change made by @TrystanLea on Jan 24 2019:

I think it’s related to not be able to set a loop on a virtual feed to it self.
Are you trying to source the same virtualfeed on the processlist ?

Hello, Chaveiro.

I think not. I try to add two feeds to have the sum in day cost.
Nevertheless, I try to add source feed; + source feed with all my feeds and no one works.

I send the image of the old config and the new (try to reproduce the same).
New installation:

Old installation:

My feeds I try to add are:

Like write, I made full clean installs and try some test feeds and always have the same problem.

Thanks for your help.

A post was split to a new topic: Problems creating virtual feed after update

Hello @nchaveiro and @TrystanLea

I made again a complete clean install on a spare Pi with the following information:

Server Information
emonhub Active Running
emoncms_mqtt Active Running
feedwriter Active Running - sleep 60s
service-runner Active Running
emonPiLCD Active Exited
redis-server Active Running
mosquitto Active Running
Emoncms Version low-write 9.9.8
Modules Administration : App v1.2.1 : Backup v1.1.6 : EmonHub Config v1.1.0 : Dashboard v1.3.3 : Device v1.2.1 : EventProcesses : Feed : Graph v1.2.3 : Input : Postprocess v1.0.0 : CoreProcess : Schedule : Network Setup v1.0.0 : sync : Time : User : Visualisation : WiFi v1.3.1
Git URL: GitHub - emoncms/emoncms: Web-app for processing, logging and visualising energy, temperature and other environmental data : Branch: * stable : Describe: v9.5.1-1775-gd0db7a57
Server OS Linux 4.14.71-v7+
Host emonpi : emonpi : (
Date 2019-04-07 08:06:30 UTC
Uptime 08:06:30 up 21 min, 0 users, load average: 0.08, 0.05, 0.03
HTTP Server Apache/2.4.25 (Raspbian) HTTP/1.1 CGI/1.1 80
MySQL Version 5.5.5-10.1.23-MariaDB-9+deb9u1
Host (
Date 2019-04-07 08:06:29 (UTC 00:00‌​)
Stats Uptime: 34289 Threads: 3 Questions: 550 Slow queries: 0 Opens: 24 Flush tables: 1 Open tables: 18 Queries per second avg: 0.016
Redis Version 3.2.6
Host localhost:6379 (
Uptime 0 days
MQTT Server Version Mosquitto 1.4.10
Host localhost:1883 (
Pi Model Raspberry Pi 2 Model B Rev 1.1 - 1 GB (Sony UK)
SoC Broadcom BCM2835
Serial num. 67A92B68
Temperature CPU: 34.70°C - GPU: 34.7’C
Release emonSD-30Oct18
Memory RAM Used: 14.81% Total: 976.74 MB Used: 144.66 MB Free: 832.08 MB
Swap Used: 0.00% Total: 100 MB Used: 0 B Free: 100 MB
Disk Mount Stats
/ Used: 39.87% Total: 3.81 GB Used: 1.52 GB Free: 2.11 GB
/boot Used: 51.69% Total: 42.52 MB Used: 21.98 MB Free: 20.54 MB
/home/pi/data Used: 3.44% Total: 3.21 GB Used: 112.81 MB Free: 2.93 GB
PHP Version 7.0.30-0+deb9u1 (Zend Version 3.0.0)
Modules apache2handler : calendar v7.0.30-0+deb9u1 : Core v7.0.30-0+deb9u1 : ctype v7.0.30-0+deb9u1 : curl v7.0.30-0+deb9u1 : date v7.0.30-0+deb9u1 : dom v20031129 : exif v7.0.30-0+deb9u1 : fileinfo v1.0.5 : filter v7.0.30-0+deb9u1 : ftp v7.0.30-0+deb9u1 : gd v7.0.30-0+deb9u1 : gettext v7.0.30-0+deb9u1 : hash v1.0 : iconv v7.0.30-0+deb9u1 : igbinary v2.0.1 : json v1.4.0 : libxml v7.0.30-0+deb9u1 : mbstring v7.0.30-0+deb9u1 : mcrypt v7.0.30-0+deb9u1 : mosquitto v0.4.0 : mysqli v7.0.30-0+deb9u1 : mysqlnd vmysqlnd 5.0.12-dev - 20150407 - $Id: b5c5906d452ec590732a93b051f3827e02749b83 $ : openssl v7.0.30-0+deb9u1 : pcre v7.0.30-0+deb9u1 : PDO v7.0.30-0+deb9u1 : pdo_mysql v7.0.30-0+deb9u1 : Phar v2.0.2 : posix v7.0.30-0+deb9u1 : readline v7.0.30-0+deb9u1 : redis v4.1.1 : Reflection v7.0.30-0+deb9u1 : session v7.0.30-0+deb9u1 : shmop v7.0.30-0+deb9u1 : SimpleXML v7.0.30-0+deb9u1 : sockets v7.0.30-0+deb9u1 : SPL v7.0.30-0+deb9u1 : standard v7.0.30-0+deb9u1 : sysvmsg v7.0.30-0+deb9u1 : sysvsem v7.0.30-0+deb9u1 : sysvshm v7.0.30-0+deb9u1 : tokenizer v7.0.30-0+deb9u1 : wddx v7.0.30-0+deb9u1 : xml v7.0.30-0+deb9u1 : xmlreader v7.0.30-0+deb9u1 : xmlwriter v7.0.30-0+deb9u1 : xsl v7.0.30-0+deb9u1 : Zend OPcache v7.0.30-0+deb9u1 : zlib v7.0.30-0+deb9u1
Client Information
HTTP Browser Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0
Screen Resolution 1525 x 858
Window Size 1506 x 730

Create the example standards physical inputs from API help, generate the the correspondent feeds. No customization made in the creation.
When try to create the virtual feed, with this feeds, the error occurs. I think in fact is a bug from the last update made by @TrystanLea, like you explain @nchaveiro.

Example of feeds add to make the virtual:

Apply the command:

It’s possible to correct this update @TrystanLea ?

Thanks for your attention and help.

4 posts were split to a new topic: Unexpected output from git describe

Should also mention I have proposed a solution to the original problem here

Thanks @borpin