VECTOR_ELT() can only be applied to a 'list', not a 'language'



This error kills all my previously working package builds.

## Clean session
> tibble::data_frame(a=1:3)
Error in cnd(.subclass, ..., message = message) : 
  VECTOR_ELT() can only be applied to a 'list', not a 'language'
> sessionInfo()
R version 3.5.1 (2018-07-02)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 17134)

Matrix products: default

[1] LC_COLLATE=German_Germany.1252  LC_CTYPE=German_Germany.1252    LC_MONETARY=German_Germany.1252
[4] LC_NUMERIC=C                    LC_TIME=German_Germany.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] compiler_3.5.1    tools_3.5.1       pillar_1.3.0.9001 rstudioapi_0.8    tibble_1.4.2     
[6] crayon_1.3.4      packrat_0.4.9-3   rlang_0.3.0      


Ok, I see: rlang_0.3.0 is guilty. Works after reinstalling rlang 0.2.2 from CRAN