Megatest

  (let* ((backupfname (conc fname"-"(current-process-id)".bak"))
	 (cmd (conc "cp "fname" "backupfname";mv "fname" "(conc fname ".delme;")
		    "cp "backupfname" "fname)))
    (dbfile:print-err "WARNING: attempting recovery of file "fname" by running commands:\n"
		      "  "cmd)
    (system cmd)))

#;(define (dbfile:cautious-open-database-orig fname init-proc #!optional (tries-left 50))
  (let* ((lock-file  (conc fname".lock"))
	 (delay-time (* (- 51 tries-left) 1.1))
	 (retry      (lambda ()
		       (thread-sleep! delay-time)
		       (if (> tries-left 0)
			   (dbfile:cautious-open-database fname init-proc (- tries-left 1))))))
    (assert (>= tries-left 0) (conc "FATAL: too many attempts in dbfile:cautious-open-database of "fname", giving up."))