Error(s) in re-building vignettes:
  ...
--- re-building ‘umap.Rmd’ using rmarkdown
 ----------- FAILURE REPORT -------------- 
 --- failure: the condition has length > 1 ---
 --- srcref --- 
: 
 --- package (from environment) --- 
umap
 --- call from context --- 
knn.from.dist(d.dist, k)
 --- call from argument --- 
if (class(d) == "dist") {
    d = as.matrix(d)
}
 --- R stacktrace ---
where 1: knn.from.dist(d.dist, k)
where 2: knn.info(d, config)
where 3: implementations[[method]](d, config)
where 4: umap(iris.data)
where 5: eval(expr, envir, enclos)
where 6: eval(expr, envir, enclos)
where 7: withVisible(eval(expr, envir, enclos))
where 8: withCallingHandlers(withVisible(eval(expr, envir, enclos)), warning = wHandler, 
    error = eHandler, message = mHandler)
where 9: handle(ev <- withCallingHandlers(withVisible(eval(expr, envir, 
    enclos)), warning = wHandler, error = eHandler, message = mHandler))
where 10: timing_fn(handle(ev <- withCallingHandlers(withVisible(eval(expr, 
    envir, enclos)), warning = wHandler, error = eHandler, message = mHandler)))
where 11: evaluate_call(expr, parsed$src[[i]], envir = envir, enclos = enclos, 
    debug = debug, last = i == length(out), use_try = stop_on_error != 
        2L, keep_warning = keep_warning, keep_message = keep_message, 
    output_handler = output_handler, include_timing = include_timing)
where 12: evaluate::evaluate(...)
where 13: evaluate(code, envir = env, new_device = FALSE, keep_warning = !isFALSE(options$warning), 
    keep_message = !isFALSE(options$message), stop_on_error = if (options$error && 
        options$include) 0L else 2L, output_handler = knit_handlers(options$render, 
        options))
where 14: in_dir(input_dir(), evaluate(code, envir = env, new_device = FALSE, 
    keep_warning = !isFALSE(options$warning), keep_message = !isFALSE(options$message), 
    stop_on_error = if (options$error && options$include) 0L else 2L, 
    output_handler = knit_handlers(options$render, options)))
where 15: block_exec(params)
where 16: call_block(x)
where 17: process_group.block(group)
where 18: process_group(group)
where 19: withCallingHandlers(if (tangle) process_tangle(group) else process_group(group), 
    error = function(e) {
        setwd(wd)
        cat(res, sep = "\n", file = output %n% "")
        message("Quitting from lines ", paste(current_lines(i), 
            collapse = "-"), " (", knit_concord$get("infile"), 
            ") ")
    })
where 20: process_file(text, output)
where 21: knitr::knit(knit_input, knit_output, envir = envir, quiet = quiet, 
    encoding = encoding)
where 22: rmarkdown::render(file, encoding = encoding, quiet = quiet, envir = globalenv(), 
    ...)
where 23: vweave_rmarkdown(...)
where 24: engine$weave(file, quiet = quiet, encoding = enc)
where 25: doTryCatch(return(expr), name, parentenv, handler)
where 26: tryCatchOne(expr, names, parentenv, handlers[[1L]])
where 27: tryCatchList(expr, classes, parentenv, handlers)
where 28: tryCatch({
    engine$weave(file, quiet = quiet, encoding = enc)
    setwd(startdir)
    output <- find_vignette_product(name, by = "weave", engine = engine)
    if (!have.makefile && vignette_is_tex(output)) {
        texi2pdf(file = output, clean = FALSE, quiet = quiet)
        output <- find_vignette_product(name, by = "texi2pdf", 
            engine = engine)
    }
}, error = function(e) {
    OK <<- FALSE
    message(gettextf("Error: processing vignette '%s' failed with diagnostics:\n%s", 
        file, conditionMessage(e)))
})
where 29: tools:::.buildOneVignette("umap.Rmd", "/home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/umap.Rcheck/vign_test/umap", 
    TRUE, FALSE, "umap", "", "/home/hornik/tmp/scratch/RtmpelMigi/file4f3dbe3e222.rds")

 --- value of length: 2 type: logical ---
[1] FALSE FALSE
 --- function from context --- 
function (d, k) 
{
    if (class(d) == "dist") {
        d = as.matrix(d)
    }
    k = floor(k)
    if (k > ncol(d)) {
        umap.error("number of neighbors must be smaller than number of items")
    }
    if (k <= 1) {
        umap.error("number of neighbors must be greater than 1")
    }
    items = 1:ncol(d)
    indexes = t(apply(d, 1, function(x) {
        items[order(x)][1:k]
    }))
    distances = matrix(0, ncol = k, nrow = nrow(d))
    for (i in 1:nrow(d)) {
        distances[i, ] = d[i, indexes[i, ]]
    }
    rownames(indexes) = rownames(distances) = rownames(d)
    list(indexes = indexes, distances = distances)
}
<bytecode: 0x55957c2e8c30>
<environment: namespace:umap>
 --- function search by body ---
Function knn.from.dist in namespace umap has this body.
 ----------- END OF FAILURE REPORT -------------- 
Fatal error: the condition has length > 1
--- re-building ‘umap_learn.Rmd’ using rmarkdown
--- finished re-building ‘umap_learn.Rmd’

SUMMARY: processing the following file failed:
  ‘umap.Rmd’

Error: Vignette re-building failed.
Execution halted