Error on vcov = 'FWB' in lm_weighit after BART weights

[joshuafayallen]

I was testing out using lm_weightit and wanted to alert you to a potential bug when FWB is specified, but doesn't error with the default or when bootstrap is specified

library(WeightIt)
library(fwb)

data(lalonde, package ='cobalt')

bart_weights = weightit(treat ~ age + educ + race +  married +
  nodegree + re74 + re75,  data = lalonde, estimand = 'ATT', method = 'bart')

lm_weightit(re78 ~ treat + age + educ + race +  married +  nodegree + re74 + re75, data = lalonde , weightit = bart_weights, vcov = 'FWB')
#> Error in `weightit()`:
#> ! Sampling weights cannot be used with `method = "bart"`.

lm_weightit(re78 ~ treat + age + educ + race +  married +  nodegree + re74 + re75, data = lalonde , weightit = bart_weights, vcov = 'BS')
#> 
#> Call:
#> lm_weightit(formula = re78 ~ treat + age + educ + race + married + 
#>     nodegree + re74 + re75, data = lalonde, weightit = bart_weights, 
#>     vcov = "BS")
#> 
#> Coefficients:
#> (Intercept)        treat          age         educ   racehispan    racewhite  
#>  -3.066e+03    1.223e+03    1.634e+01    6.395e+02    1.640e+03    1.093e+03  
#>     married     nodegree         re74         re75  
#>   2.584e+02    7.523e+02    8.859e-02    1.196e-01  
#> Standard error: traditional bootstrap

lm_weightit(re78 ~ treat + age + educ + race +  married +  nodegree + re74 + re75, data = lalonde, weightit = bart_weights)
#> 
#> Call:
#> lm_weightit(formula = re78 ~ treat + age + educ + race + married + 
#>     nodegree + re74 + re75, data = lalonde, weightit = bart_weights)
#> 
#> Coefficients:
#> (Intercept)        treat          age         educ   racehispan    racewhite  
#>  -3.066e+03    1.223e+03    1.634e+01    6.395e+02    1.640e+03    1.093e+03  
#>     married     nodegree         re74         re75  
#>   2.584e+02    7.523e+02    8.859e-02    1.196e-01  
#> Standard error: HC0 robust

^{Created on 2024-07-17 with reprex v2.1.1}

[ngreifer]

Thanks for letting me know about this. Unfortunately, this is not a solvable problem, but I'll put a clearer error message identifying that vcov = "FWB" cannot be used with BART.