GC 2.6.99 built from git rev d96bb3ebd+ corrupts MySQL db

[Art]

I built it under Ubuntu 17.04 after a git download with,
 ./configure --enable-dbi --prefix=/opt/gnucash-devel --enable-compile-warnings --with-html-engine=webkit --enable-ofx Options detected/selected
  -------------------------
  gnucash version ...... : 2.6.99
  Build for host ....... : x86_64-pc-linux-gnu
  Optional components... :  dbi ofx
  Extra Warnings ....... :  -Werror -Wdeclaration-after-statement -Wno-pointer-sign -D_FORTIFY_SOURCE=2
  CPPFLAGS ............. : 
  CFLAGS ............... : -g -O2 -std=gnu11
  CXXFLAGS ............. : -g -O2
  LDFLAGS .............. :  
  prefix................ : /opt/gnucash-devel

XML works fine, but the MySQL db now gets corrupted. It was working fine with GC v2.6.15.I am not familiar enough with the backend dbi to troubleshoot, but I see that,/tmp/gnucash.trace:* 16:51:34  INFO <gnc.engine> [gnc_hook_lookup] no hook lists
* 16:51:35  INFO <gnc.backend.dbi> [gnc_module_init_backend_dbi] GNC_DBD_DIR not set: using libdbi built-in default
* 16:51:35  INFO <gnc.backend.dbi> [gnc_module_init_backend_dbi] 1 DBD drivers found
* 16:51:35  INFO <gnc.backend.dbi> [gnc_module_init_backend_dbi] Driver: mysql
* 16:51:36 MESSG <gnc.module> Could not locate optional module gnucash/import-export/aqbanking interface v.0
* 16:51:40 MESSG <gnc.module> Could not locate optional module gnucash/python interface v.0
* 16:51:40 MESSG <gnc.bin> loading system configuration
...So I assumed it should be working, but as soon as I do a file open on my db, I get a pop-up, The server at URL mysql://root@localhost/gc2017 experienced an error or encountered bad or corrupt data.
When I look at the db with the workbench I notice that the "accounts" table has been backed up to "accounts_back" and the "accounts" table now has two records with field name "Root Account", account_type="ROOT" with a guid field. At this point, the db is corrupt. I don't want to revert to GC 2.6.15 if I can fix this. I want to keep using MySQL and I can't just save an XML to MySQL because it also reports that the db is corrupt. So, I must be making a fundamental mistake or series thereof because I haven't heard anyone else complain about any issues with the MySQL backend. Maybe I'm pulling the wrong version? I am only using git at this point to get the source code.

Thanks,Art