r - RMarkdown will not render from Rscript with sqlite connection -

i unable render rmarkdown documents rscript if have dplyr sqlite calls in them. take mwe (test.rmd) calls table in local copy of dplyr::lahman_sqlite() table.

--- title: "testfile" output: html_document ---  ```{r setup, include=false} library(dplyr) lahman <- src_sqlite("lahman.sqlite") ```  ```{r} tbl(lahman, "batting") ``` 

in live r console session can call rmarkdown::render("test.rmd"), , document built expected. if call rscript -e 'rmarkdown::render("test.rmd")' on command line, following error:

quitting lines 12-13 (test.rmd) error in usemethod("db_query_fields") :   no applicable method 'db_query_fields' applied object of class "sqliteconnection" calls: render ... make_tbl -> structure -> op_base_remote -> db_query_fields 

i've attached sessioninfo below, i've duplicated error on os x ubuntu.

r version 3.3.1 (2016-06-21) platform: x86_64-apple-darwin15.5.0 (64-bit) running under: os x 10.11.6 (el capitan)  locale: [1] en_us.utf-8/en_us.utf-8/en_us.utf-8/c/en_us.utf-8/en_us.utf-8  attached base packages: [1] stats     graphics  grdevices utils     datasets  methods   base       other attached packages: [1] dplyr_0.5.0  loaded via namespace (and not attached):  [1] rcpp_0.12.5     digest_0.6.9    assertthat_0.1  r6_2.1.2        dbi_0.4-1       formatr_1.4     magrittr_1.5    evaluate_0.9     [9] rsqlite_1.0.0   stringi_1.1.1   rmarkdown_0.9.6 tools_3.3.1     stringr_1.0.0   lahman_4.0-1    yaml_2.1.13     htmltools_0.3.5 [17] knitr_1.13      tibble_1.0   

the problem comes fact when using rscript methods package not loaded. it's therefore required load explicitly adding library(methods) in setup chunk instance.