Being aware of the danger of using dynamic variable names, I am trying to loop over varios regression models where different variables specifications are choosen. Usually `!!rlang::sym()` solves this kind of problem for me just fine, but it somehow fails in regressions. A minimal example would be the following:

```
y= runif(1000) 
x1 = runif(1000) 
x2 = runif(1000) 

df2= data.frame(y,x1,x2)
summary(lm(y ~ x1+x2, data=df2)) ## works

var = "x1"
summary(lm(y ~ !!rlang::sym(var)) +x2, data=df2) # gives an error

```

My understanding was that `!!rlang::sym(var))` takes the values of `var` (namely x1) and puts that in the code in a way that R thinks this is a variable (not a char). BUt I seem to be wrong. Can anyone enlighten me?