Report the LaTeX error from stderr when build_manual() fails

NEWS.md

@@ -1,5 +1,6 @@
 # devtools (development version)
 
+* `build_manual()` reports more details on failure (#2586).
 * New `check_mac_devel()` function to check a package using the macOS builder at https://mac.r-project.org/macbuilder/submit.html (@nfrerebeau, #2507)
 * `is_loading()` is now re-exported from pkgload (#2556).
 * `load_all()` now errors if called recursively, i.e. if you accidentally include a `load_all()` call in one of your R source files (#2617).

R/build-manual.R

@@ -9,25 +9,28 @@
 build_manual <- function(pkg = ".", path = NULL) {
   pkg <- as.package(pkg)
   path <- path %||% path_dir(pkg$path)
-  name <- paste0(pkg$package, "_", pkg$version, ".pdf", collapse = " ")
-  tryCatch(
-    msg <- callr::rcmd(
-      "Rd2pdf",
-      cmdargs = c(
-        "--force",
-        paste0("--output=", path, "/", name),
-        pkg$path
-      ),
-      fail_on_status = TRUE,
-      stderr = "2>&1",
-      spinner = FALSE
-    ),
+  name <- paste0(pkg$package, "_", pkg$version, ".pdf")
+  output <- file.path(path, name)
+
+  cli::cli_inform("Saving manual to {.file {output}}")
+  withCallingHandlers(
+    invisible(rd2pdf(pkg$path, output)),
     error = function(e) {
-      cat(e$stdout)
-      cli::cli_abort("Failed to build manual")
+      cli::cli_abort(
+        c("Failed to build manual.", no_wrap(e$stderr)),
+        call = quote(build_manual()),
+        parent = e
+      )
     }
   )
+}
 
-  cat(msg$stdout)
-  invisible(msg)
+rd2pdf <- function(pkg_path, output_path) {
+  callr::rcmd(
+    "Rd2pdf",
+    cmdargs = c("--force", paste0("--output=", output_path), pkg_path),
+    stdout = "",
+    fail_on_status = TRUE,
+    spinner = FALSE
+  )
 }

R/utils.R

@@ -44,3 +44,10 @@ is_testing <- function() {
 is_rstudio_running <- function() {
   !is_testing() && rstudioapi::isAvailable()
 }
+
+# Suppress cli wrapping
+no_wrap <- function(x) {
+  x <- gsub(" ", "\u00a0", x, fixed = TRUE)
+  x <- gsub("\n", "\f", x, fixed = TRUE)
+  x
+}

tests/testthat/_snaps/build-manual.md

@@ -0,0 +1,13 @@
+# build_manual() shows stderr on failure
+
+    Code
+      build_manual(pkg)
+    Message
+      Saving manual to '<pkgdir>_0.0.0.9000.pdf'
+    Condition
+      Error in `build_manual()`:
+      ! Failed to build manual.
+      ! LaTeX Error: File `inconsolata.sty' not found.
+      Caused by error in `rd2pdf()`:
+      ! System command 'R' failed
+

tests/testthat/test-build-manual.R

@@ -0,0 +1,17 @@
+test_that("build_manual() shows stderr on failure", {
+  skip_on_os("windows")
+
+  pkg <- local_package_create()
+  pkg <- normalizePath(pkg)
+
+  # Too hard to replicate actual error, so we just simulate
+  local_mocked_bindings(rd2pdf = function(...) {
+    stderr <- "! LaTeX Error: File `inconsolata.sty' not found."
+    rlang::abort("System command 'R' failed", stderr = stderr) #nolint
+  })
+
+  expect_snapshot(build_manual(pkg), error = TRUE, transform = function(x) {
+    x <- gsub(pkg, "<pkgdir>", x, fixed = TRUE)
+    x
+  })
+})