library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union

df <-
  tibble(a = 1, a = 3:2, .name_repair = "minimal") %>%
  rlang::set_names(c("", "a"))

df
#> # A tibble: 2 x 2
#>      ``     a
#>   <dbl> <int>
#> 1     1     3
#> 2     1     2

df %>%
  select(a)
#> # A tibble: 2 x 1
#>       a
#>   <int>
#> 1     3
#> 2     2

df %>%
  filter(a == 1)
#> Error in filter_impl(.data, quo): Evaluation error: attempt to use zero-length variable name.

df %>%
  mutate(b = 2)
#> # A tibble: 2 x 3
#>      ``     a     b
#>   <dbl> <int> <dbl>
#> 1     1     3     2
#> 2     1     2     2

df %>%
  mutate(c = a)
#> # A tibble: 2 x 3
#>      ``     a     c
#>   <dbl> <int> <int>
#> 1     1     3     3
#> 2     1     2     2

df %>%
  arrange(a)
#> Error in arrange_impl(.data, dots): Evaluation error: attempt to use zero-length variable name.

df %>%
  summarize(b = sum(a))
#> # A tibble: 1 x 1
#>       b
#>   <int>
#> 1     5

df %>%
  group_by(a) %>%
  summarize(b = sum(a))
#> # A tibble: 2 x 2
#>       a     b
#>   <int> <int>
#> 1     2     2
#> 2     3     3

^{Created on 2018-11-19 by the reprex package (v0.2.1.9000)}