Unexpected end of JSON input

[xanxanxan]

Whenever I try to render an audiogram (i can start to render in fact but around "generating frames, 2%", it crashes), the application encounters an "Unexpected end of JSON input".
In the user interface, I get

{"readyState":0,"status":0,"statusText":"error"}

just beneath "Audiogram" and in the terminal, I get

[email protected] start /home/troth/audiogram
npm run postinstall && bin/server

[email protected] postinstall /home/troth/audiogram
mkdir -p editor/js && browserify client/index.js > editor/js/bundle.js

info: Listening on 8888
undefined:1

SyntaxError: Unexpected end of JSON input
at JSON.parse ()
at load (/home/troth/audiogram/lib/transports/redis/fake.js:14:15)
at update (/home/troth/audiogram/lib/transports/redis/fake.js:24:12)
at Object.addJob (/home/troth/audiogram/lib/transports/redis/fake.js:72:5)
at WriteStream. (/home/troth/audiogram/server/render.js:48:16)
at emitNone (events.js:91:20)
at WriteStream.emit (events.js:185:7)
at fs.js:1871:14
at FSReqWrap.oncomplete (fs.js:111:15)

npm ERR! Linux 3.13.0-108-generic
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "start"
npm ERR! node v7.2.1
npm ERR! npm v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! [email protected] start: npm run postinstall && bin/server
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] start script 'npm run postinstall && bin/server'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the audiogram package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! npm run postinstall && bin/server
npm ERR! You can get information on how to open an issue for this project with:
npm ERR! npm bugs audiogram
npm ERR! Or if that isn't available, you can get their info via:
npm ERR! npm owner ls audiogram
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR! /home/xan/audiogram/npm-debug.log

npm-debug.log says:

0 info it worked if it ends with ok
1 verbose cli [ '/usr/local/bin/node', '/usr/local/bin/npm', 'start' ]
2 info using [email protected]
3 info using [email protected]
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle [email protected]prestart: [email protected]
6 silly lifecycle [email protected]prestart: no script for prestart, continuing
7 info lifecycle [email protected]start: [email protected]
8 verbose lifecycle [email protected]start: unsafe-perm in lifecycle true
9 verbose lifecycle [email protected]start: PATH: /usr/local/lib/node_modules/npm/bin/node-gyp-bin:/home/troth/audiogram/node_modules/.bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
10 verbose lifecycle [email protected]start: CWD: /home/troth/audiogram
11 silly lifecycle [email protected]start: Args: [ '-c', 'npm run postinstall && bin/server' ]
12 silly lifecycle [email protected]start: Returned: code: 1 signal: null
13 info lifecycle [email protected]~start: Failed to exec start script
14 verbose stack Error: [email protected] start: npm run postinstall && bin/server
14 verbose stack Exit status 1
14 verbose stack at EventEmitter. (/usr/local/lib/node_modules/npm/lib/utils/lifecycle.js:255:16)
14 verbose stack at emitTwo (events.js:106:13)
14 verbose stack at EventEmitter.emit (events.js:191:7)
14 verbose stack at ChildProcess. (/usr/local/lib/node_modules/npm/lib/utils/spawn.js:40:14)
14 verbose stack at emitTwo (events.js:106:13)
14 verbose stack at ChildProcess.emit (events.js:191:7)
14 verbose stack at maybeClose (internal/child_process.js:885:16)
14 verbose stack at Process.ChildProcess._handle.onexit (internal/child_process.js:226:5)
15 verbose pkgid [email protected]
16 verbose cwd /home/troth/audiogram
17 error Linux 3.13.0-108-generic
18 error argv "/usr/local/bin/node" "/usr/local/bin/npm" "start"
19 error node v7.2.1
20 error npm v3.10.10
21 error code ELIFECYCLE
22 error [email protected] start: npm run postinstall && bin/server
22 error Exit status 1
23 error Failed at the [email protected] start script 'npm run postinstall && bin/server'.
23 error Make sure you have the latest version of node.js and npm installed.
23 error If you do, this is most likely a problem with the audiogram package,
23 error not with npm itself.
23 error Tell the author that this fails on your system:
23 error npm run postinstall && bin/server
23 error You can get information on how to open an issue for this project with:
23 error npm bugs audiogram
23 error Or if that isn't available, you can get their info via:
23 error npm owner ls audiogram
23 error There is likely additional logging output above.
24 verbose exit [ 1, true ]

The strange thing is that some days ago, audiogram worked on this very machine. Maybe I installed distro upgrades but I didn’t change anything specific to my audiogram setup. I’d greatly appreciate any help on this.

[veltman]

It's possible that your jobs file got corrupted, so deleting [folder where you installed Audiogram]/.jobs could be a temporary fix for this.

A more permanent fix is to use Redis as described here: #63 (comment)