[1] "have"                           "argument `x` as first argument"
[3] ""                               ""

# FALSE - defaults in target must be specified in current as well

# FALSE dots in target must exit in current

[1] "have"                              "argument `...` after argument `x`"
[3] ""                                  ""

# FALSE - all arguments in target must be in current, even with dots

[1] "have"                              "argument `y` after argument `...`"
[3] ""                                  ""

# FALSE - extra arguments in current must be adjacent to dots

[1] "not have"                        "argument `w` after argument `y`"
[3] ""                                ""

[1] "have"                                
[2] "argument `env` after argument `expr`"
[3] ""                                    
[4] ""

[1] "have"                              "argument `expr` as first argument"
[3] ""                                  ""

[1] "not have"      "any arguments" ""              ""

Error in vetr:::fun_alike(identity, 10) : Arguments must be functions.

Error in vetr:::fun_alike(10, identity) : Arguments must be functions.

# Overwhelm env stack, though not that satifying a test

All contents of `env` should be environments; error  at item 1

Error in vetr:::env_track(list(1, 2, 3), 1L, 3L) : 
  All contents of `env` should be environments; error  at item 1

Error in vetr:::is_valid_name(letters) : 
  Argument `name` must be character(1L)

vetr:::pad_or_quote(quote(1 + 1), syntactic = 0L)

vetr:::pad_or_quote(quote(1 + 1), syntactic = 1L)

Internal Error: unexpected string format to merge; contact maintainer

Error in vetr:::msg_sort(list(letters[1:5], NULL)) : 
  Internal Error: unexpected string format to merge; contact maintainer

Error in vetr:::msg_sort(letters) : Expected list argument, got character

[[1]]
[1] "`my_var`"  "be"        "integer"   "is"        "character"

`attr(my_var)` should be "NULL" (is list)

`length(names(my_var))` should be 2, or 3 (is 4)

`my_var` should be "NULL", integer, or matrix (is character)