R：运行debugSource时fBody [[i]]中出现错误

我有一个大约1400行的R脚本。我最近开始收到以下错误消息。我可以通过突出显示并使用ctrl-R来运行脚本，但无法在调试模式下运行脚本。关于如何找到错误的任何建议？

> debugSource('~/working/R/h60_maintenance/do_mega_analysis.R')
Error in fBody[[i]] : subscript out of bounds
> options(error=recover)
> debugSource('~/working/R/h60_maintenance/do_mega_analysis.R')
Error in fBody[[i]] : subscript out of bounds
Enter a frame number, or 0 to exit   
 1: debugSource("~/working/R/h60_maintenance/do_mega_analysis.R")
 2: (function (fileName, encoding, breaklines) 
{
    env <- new.env(parent = emptyenv())
    env$fun <- 
 3: suppressWarnings(.rs.setFunctionBreakpoints("fun", env, lapply(steps, function(step) {
    step$at
}
 4: withCallingHandlers(expr, warning = function(w) invokeRestart("muffleWarning"))
 5: .rs.setFunctionBreakpoints("fun", env, lapply(steps, function(step) {
    step$at
}))
 6: suppressMessages(trace(what = functionName, where = envir, at = lapply(strsplit(as.character(steps
 7: withCallingHandlers(expr, message = function(c) invokeRestart("muffleMessage"))
 8: trace(what = functionName, where = envir, at = lapply(strsplit(as.character(steps), ","), as.numer
 9: eval.parent(call)
10: eval(expr, p)
11: eval(expr, envir, enclos)
12: methods::.TraceWithMethods(what = functionName, where = <environment>, at = lapply(strsplit(as.cha
13: new(traceClass, def = if (doEdit) def else original, tracer = tracer, exit = exit, at = at, print 
14: initialize(value, ...)
15: initialize(value, ...)
16: .initTraceable(.Object, ...)
17: .makeTracedFunction(def, tracer, exit, at, print, doEdit)

该错误可能与以下几行有关，因为这些行与选项10相关联：eval（expr，p）。

imds_rollup <- imds_detail_dt[,{
  ## if there's just one row in the group of ID's, return nothing
  list(
    count_every_fault = .N,
    max_ci_value = max(CI.Value),
    max_rotor_turn_time_air_sec = max(Rotor.Turn.Time...In.Air..s.),
    max_rotor_turn_time_ground_sec = max(Rotor.Turn.Time...On.Ground..s.)
  )}, by = c("BUNO","fileEventIndex")]
setkeyv(imds_rollup,c("BUNO","fileEventIndex"))
imds_rollup$max_ci_value <- NULL   # max_ci_value has all NA