error in bitbake <target>

while executing bitbake meta-toolchain i got error

ERROR: Error parsing configuration files
Traceback (most recent call last):
File “/fsl-release-bsp/sources/poky/bitbake/lib/bb/”, line 239, in CookerDataBuilder.parseBaseConfiguration():
> self.parseConfigurationFiles(self.prefiles, self.postfiles)
except SyntaxError:
File “/fsl-release-bsp/sources/poky/bitbake/lib/bb/”, line 304, in CookerDataBuilder.parseConfigurationFiles(prefiles=[], postfiles=[]):
if data.getVar(“BB_WORKERCONTEXT”, False) is None:
> bb.fetch.fetcher_init(data)
File “/fsl-release-bsp/sources/poky/bitbake/lib/bb/fetch2/”, line 490, in fetcher_init(d=):
> revs.clear()
File “/fsl-release-bsp/sources/poky/bitbake/lib/bb/”, line 147, in SQLTable.clear():
def clear(self):
> self._execute(“DELETE FROM %s;” % self.table)

File “/fsl-release-bsp/sources/poky/bitbake/lib/bb/”, line 66, in SQLTable._execute(*query=(‘DELETE FROM BB_URI_HEADREVS;’,)):
> return self.cursor.execute(*query)
except sqlite3.OperationalError as exc:
OperationalError: attempt to write a readonly database
how to fix it?

are you able to build regular images? what version of DEY are you using? what platform? I would start from scratch on a clean system.