Upgrading to Version 7 (Develop) Error

I have tried switching to the develop branch but am having issues:

Migrating erpnext.vm
Executing erpnext.patches.v4_2.repost_reserved_qty #2016-04-15 in erpnext.vm (d56cb677ea)
Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/home/frappe/frappe-bench/apps/frappe/frappe/utils/bench_helper.py", line 79, in <module>
    main()
  File "/home/frappe/frappe-bench/apps/frappe/frappe/utils/bench_helper.py", line 16, in main
    click.Group(commands=commands)(prog_name='bench')
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 716, in __call__
    return self.main(*args, **kwargs)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 696, in main
    rv = self.invoke(ctx)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 889, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/commands/__init__.py", line 24, in _func
    ret = f(frappe._dict(ctx.obj), *args, **kwargs)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/commands/site.py", line 163, in migrate
    migrate(context.verbose, rebuild_website=rebuild_website)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/migrate.py", line 27, in migrate
    frappe.modules.patch_handler.run_all()
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/patch_handler.py", line 25, in run_all
    if not run_single(patchmodule = patch):
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/patch_handler.py", line 52, in run_single
    return execute_patch(patchmodule, method, methodargs)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/patch_handler.py", line 68, in execute_patch
    frappe.get_attr(patchmodule.split()[0] + ".execute")()
  File "/home/frappe/frappe-bench/apps/erpnext/erpnext/patches/v4_2/repost_reserved_qty.py", line 10, in execute
    frappe.reload_doctype(doctype)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/__init__.py", line 600, in reload_doctype
    reload_doc(scrub(db.get_value("DocType", doctype, "module")), "doctype", scrub(doctype), force=force)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/__init__.py", line 612, in reload_doc
    return frappe.modules.reload_doc(module, dt, dn, force=force)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/__init__.py", line 37, in reload_doc
    return import_files(module, dt, dn, force=force)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/import_file.py", line 17, in import_files
    return import_file(module, dt, dn, force=force, pre_process=pre_process)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/import_file.py", line 22, in import_file
    ret = import_file_by_path(path, force, pre_process=pre_process)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/import_file.py", line 54, in import_file_by_path
    import_doc(doc, force=force, data_import=data_import, pre_process=pre_process)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/modules/import_file.py", line 122, in import_doc
    doc.insert()
  File "/home/frappe/frappe-bench/apps/frappe/frappe/model/document.py", line 205, in insert
    self.db_insert()
  File "/home/frappe/frappe-bench/apps/frappe/frappe/model/base_document.py", line 283, in db_insert
    ), d.values())
  File "/home/frappe/frappe-bench/apps/frappe/frappe/database.py", line 136, in sql
    self._cursor.execute(query, values)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/cursors.py", line 205, in execute
    self.errorhandler(self, exc, value)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
_mysql_exceptions.OperationalError: (1048, "Column 'beta' cannot be null")
Traceback (most recent call last):
  File "/usr/local/bin/bench", line 9, in <module>
    load_entry_point('bench==0.92', 'console_scripts', 'bench')()
  File "/home/frappe/bench-repo/bench/cli.py", line 40, in cli
    bench_command()
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 716, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 696, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 889, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "/home/frappe/bench-repo/bench/commands/update.py", line 61, in update
    _update(pull, patch, build, bench, auto, restart_supervisor, requirements, no_backup, upgrade, force=force)
  File "/home/frappe/bench-repo/bench/commands/update.py", line 91, in _update
    patch_sites(bench=bench_path)
  File "/home/frappe/bench-repo/bench/utils.py", line 132, in patch_sites
    run_frappe_cmd('--site', 'all', 'migrate', bench=bench)
  File "/home/frappe/bench-repo/bench/utils.py", line 492, in run_frappe_cmd
    raise CommandFailedError(args)
bench.utils.CommandFailedError: ('--site', 'all', 'migrate')

This is being run on a virtual instance on my computer.

Did you switch for both ERPNext and Frappe?

I used the bench switch-to-develop command, which I think does both. When I first tried to switch I ran into issues because I had accidentally modified one of the erpnext files, so I needed to use git reset --hard to get it to work.