x <- Macro[1:13,3:21]
x <- as.matrix(x)
x
y <- Macro[1:13,2:2]
y <- as.matrix(y)
y

ctrl2 = trainControl(
  method = "cv",
  number = 2,
  verboseIter = TRUE
 )

myfit <- caret::train(y ~ .,
                  data = x,
                  method = "lm",
                  trControl = ctrl2)

Error in data[, all.vars(Terms), drop = FALSE] : subscript out of bounds
In addition: Warning messages:
1: In predict.lm(modelFit, newdata) :
prediction from a rank-deficient fit may be misleading