https://github.com/spesmilo/electrum-server/blob/master/HOWTO.md
Step 4.
Database not found in /var/electrum-server.
Do you want to download it from the Electrum foundry to /var/electrum-server ?
chown: invalid user: ‘electrum:electrum’
warning: no files found matching '*' under directory 'doc/build/html'
warning: no files found matching 'plyvel/*.pxi'
cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
plyvel/_plyvel.cpp:359:24: fatal error: leveldb/db.h: No such file or directory
#include "leveldb/db.h"
^
compilation terminated.
error: Setup script exited with error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
Reading package lists... Done
Building dependency tree
Reading state information... Done
gcc is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
I ran into this same issue. I had to run the following first: sudo apt-get install libleveldb-dev