From f28dfc8b1b678a7fb45b45f1d49bd3eb2edf9f0b Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Fri, 12 Apr 2024 08:09:37 -0500
Subject: [PATCH 1/9] Improve rmarkdown error forwarding

Part of #2433
---
 R/rmarkdown.R                      | 6 ++++--
 tests/testthat/_snaps/rmarkdown.md | 2 --
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/R/rmarkdown.R b/R/rmarkdown.R
index 1dd09d73d..14eea2f87 100644
--- a/R/rmarkdown.R
+++ b/R/rmarkdown.R
@@ -25,7 +25,7 @@ render_rmarkdown <- function(pkg, input, output, ..., seed = NULL, copy_images =
     quiet = quiet
   )
 
-  path <- tryCatch(
+  path <- withCallingHandlers(
     callr::r_safe(
       function(seed, envir, ...) {
         if (!is.null(seed)) {
@@ -51,12 +51,14 @@ render_rmarkdown <- function(pkg, input, output, ..., seed = NULL, copy_images =
       )
     ),
     error = function(cnd) {
+      # browser()
       cli::cli_abort(
         c(
           "Failed to render RMarkdown document.",
           x = gsub("\r", "", cnd$stderr, fixed = TRUE)
         ),
-        parent = cnd
+        parent = cnd$parent,
+        trace = cnd$parent$trace
       )
     }
   )
diff --git a/tests/testthat/_snaps/rmarkdown.md b/tests/testthat/_snaps/rmarkdown.md
index aa84604f5..b6d077fce 100644
--- a/tests/testthat/_snaps/rmarkdown.md
+++ b/tests/testthat/_snaps/rmarkdown.md
@@ -18,8 +18,6 @@
       ! Failed to render RMarkdown document.
       x [WARNING] Could not fetch resource path-to-image.png Failing because there were warnings.
       Caused by error:
-      ! in callr subprocess.
-      Caused by error:
       ! pandoc document conversion failed with error 3
 
 # render_rmarkdown styles ANSI escapes

From 8725e3cb1d7dbe57abf38e75b3c82ff88fc33c9f Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 08:27:19 -0500
Subject: [PATCH 2/9] Tweaks from code review

---
 R/rmarkdown.R | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/R/rmarkdown.R b/R/rmarkdown.R
index 14eea2f87..7f8f44e68 100644
--- a/R/rmarkdown.R
+++ b/R/rmarkdown.R
@@ -51,13 +51,12 @@ render_rmarkdown <- function(pkg, input, output, ..., seed = NULL, copy_images =
       )
     ),
     error = function(cnd) {
-      # browser()
       cli::cli_abort(
         c(
           "Failed to render RMarkdown document.",
           x = gsub("\r", "", cnd$stderr, fixed = TRUE)
         ),
-        parent = cnd$parent,
+        parent = cnd$parent %||% cnd,
         trace = cnd$parent$trace
       )
     }

From 6c3efdec3edfa3ed9d43c42a8150b17a59b99495 Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 08:36:59 -0500
Subject: [PATCH 3/9] Try snapshoting traceback too

---
 tests/testthat/_snaps/rmarkdown.md | 18 ++++++++++++++++++
 tests/testthat/assets/r-fail.Rmd   | 13 +++++++++++++
 tests/testthat/test-rmarkdown.R    |  9 +++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 tests/testthat/assets/r-fail.Rmd

diff --git a/tests/testthat/_snaps/rmarkdown.md b/tests/testthat/_snaps/rmarkdown.md
index b6d077fce..b9ba50fcd 100644
--- a/tests/testthat/_snaps/rmarkdown.md
+++ b/tests/testthat/_snaps/rmarkdown.md
@@ -20,6 +20,24 @@
       Caused by error:
       ! pandoc document conversion failed with error 3
 
+---
+
+    Code
+      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
+    Message
+      Reading assets/r-fail.Rmd
+    Condition
+      Error in `render_rmarkdown()`:
+      ! Failed to render RMarkdown document.
+      x Quitting from lines at lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
+      Caused by error:
+      ! Error!
+    Code
+      last_trace()
+    Condition
+      Error:
+      ! Can't show last error because no error was recorded yet
+
 # render_rmarkdown styles ANSI escapes
 
     Code
diff --git a/tests/testthat/assets/r-fail.Rmd b/tests/testthat/assets/r-fail.Rmd
new file mode 100644
index 000000000..101dc46a0
--- /dev/null
+++ b/tests/testthat/assets/r-fail.Rmd
@@ -0,0 +1,13 @@
+---
+title: "r-fail"
+---
+
+```{r}
+f <- function() g()
+g <- function() h()
+h <- function() {
+  rlang::abort("Error!")
+}
+
+f()
+```
\ No newline at end of file
diff --git a/tests/testthat/test-rmarkdown.R b/tests/testthat/test-rmarkdown.R
index 24b3af222..e35e87307 100644
--- a/tests/testthat/test-rmarkdown.R
+++ b/tests/testthat/test-rmarkdown.R
@@ -21,12 +21,21 @@ test_that("render_rmarkdown yields useful error", {
   tmp <- dir_create(file_temp())
   pkg <- list(src_path = test_path("."), dst_path = tmp, bs_version = 3)
 
+  # For pandoc
   expect_snapshot(error = TRUE, {
     render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html",
         output_format = rmarkdown::html_document(pandoc_args = "--fail-if-warnings"))
   })
+
+  expect_snapshot(error = TRUE, {
+    render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
+    last_trace()
+  })
+
 })
 
+
+
 test_that("render_rmarkdown styles ANSI escapes", {
   skip_if_no_pandoc()
   local_edition(3)

From 3c30089e0bba31930f27597a7339eaadb031c2ef Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 08:38:11 -0500
Subject: [PATCH 4/9] WS

---
 tests/testthat/test-rmarkdown.R | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tests/testthat/test-rmarkdown.R b/tests/testthat/test-rmarkdown.R
index e35e87307..6e12d4794 100644
--- a/tests/testthat/test-rmarkdown.R
+++ b/tests/testthat/test-rmarkdown.R
@@ -34,8 +34,6 @@ test_that("render_rmarkdown yields useful error", {
 
 })
 
-
-
 test_that("render_rmarkdown styles ANSI escapes", {
   skip_if_no_pandoc()
   local_edition(3)

From 512b2f01598572d2da83c8b43904b559ee9f723c Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 09:02:45 -0500
Subject: [PATCH 5/9] Option to build in process

---
 R/rmarkdown.R                      | 84 ++++++++++++++++--------------
 tests/testthat/_snaps/rmarkdown.md | 32 +++++++-----
 tests/testthat/test-rmarkdown.R    | 13 +++--
 3 files changed, 70 insertions(+), 59 deletions(-)

diff --git a/R/rmarkdown.R b/R/rmarkdown.R
index 7f8f44e68..fc22fc66d 100644
--- a/R/rmarkdown.R
+++ b/R/rmarkdown.R
@@ -1,7 +1,7 @@
 #' Render RMarkdown document in a fresh session
 #'
 #' @noRd
-render_rmarkdown <- function(pkg, input, output, ..., seed = NULL, copy_images = TRUE, quiet = TRUE) {
+render_rmarkdown <- function(pkg, input, output, ..., seed = NULL, copy_images = TRUE, new_process = TRUE, quiet = TRUE, call = caller_env()) {
 
   input_path <- path_abs(input, pkg$src_path)
   output_path <- path_abs(output, pkg$dst_path)
@@ -19,49 +19,39 @@ render_rmarkdown <- function(pkg, input, output, ..., seed = NULL, copy_images =
     output_dir = path_dir(output_path),
     intermediates_dir = tempdir(),
     encoding = "UTF-8",
-    envir = globalenv(),
     seed = seed,
     ...,
     quiet = quiet
   )
 
-  path <- withCallingHandlers(
-    callr::r_safe(
-      function(seed, envir, ...) {
-        if (!is.null(seed)) {
-          # since envir is copied from the parent fn into callr::r_safe(),
-          # set.seed() sets the seed in the wrong global env and we have to
-          # manually copy it over
-          set.seed(seed)
-          envir$.Random.seed <- .GlobalEnv$.Random.seed
-          if (requireNamespace("htmlwidgets", quietly = TRUE)) {
-            htmlwidgets::setWidgetIdSeed(seed)
-          }
-        }
-        rmarkdown::render(envir = envir, ...)
-      },
-      args = args,
-      show = !quiet,
-      env = c(
-        callr::rcmd_safe_env(),
-        BSTINPUTS = bst_paths(input_path),
-        TEXINPUTS = tex_paths(input_path),
-        BIBINPUTS = bib_paths(input_path),
-        R_CLI_NUM_COLORS = 256
-      )
-    ),
-    error = function(cnd) {
-      cli::cli_abort(
-        c(
-          "Failed to render RMarkdown document.",
-          x = gsub("\r", "", cnd$stderr, fixed = TRUE)
-        ),
-        parent = cnd$parent %||% cnd,
-        trace = cnd$parent$trace
-      )
-    }
+  withr::local_envvar(
+    callr::rcmd_safe_env(),
+    BSTINPUTS = bst_paths(input_path),
+    TEXINPUTS = tex_paths(input_path),
+    BIBINPUTS = bib_paths(input_path),
+    R_CLI_NUM_COLORS = 256
   )
 
+  if (new_process) {
+    path <- withCallingHandlers(
+      callr::r_safe(rmarkdown_render_with_seed, args = args, show = !quiet),
+      error = function(cnd) {
+        lines <- strsplit(cnd$stderr, "\r?\n")[[1]]
+        cli::cli_abort(
+          c(
+            x = "Failed to render RMarkdown document.",
+            set_names(lines, " ")
+          ),
+          parent = cnd$parent %||% cnd,
+          trace = cnd$parent$trace,
+          call = call
+        )
+      }
+    )
+  } else {
+    path <- inject(rmarkdown_render_with_seed(!!!args))
+  }
+
   if (identical(path_ext(path)[[1]], "html")) {
     update_html(
       path,
@@ -103,6 +93,25 @@ render_rmarkdown <- function(pkg, input, output, ..., seed = NULL, copy_images =
   invisible(path)
 }
 
+
+rmarkdown_render_with_seed <- function(..., seed = NULL) {
+  if (!is.null(seed)) {
+    set.seed(seed)
+    if (requireNamespace("htmlwidgets", quietly = TRUE)) {
+      htmlwidgets::setWidgetIdSeed(seed)
+    }
+
+    # since envir is copied from the parent fn into callr::r_safe(),
+    # set.seed() sets the seed in the wrong global env and we have to
+    # manually copy it over
+    # if (!identical(envir, globalenv())) {
+    #   envir$.Random.seed <- .GlobalEnv$.Random.seed
+    # }
+  }
+ 
+  rmarkdown::render(envir = globalenv(), ...)
+}
+
 # adapted from tools::texi2dvi
 bst_paths <- function(path) {
   paths <- c(
@@ -126,5 +135,4 @@ bib_paths <- function(path) {
     tex_paths(path)
   )
   paste(paths, collapse = .Platform$path.sep)
-
 }
diff --git a/tests/testthat/_snaps/rmarkdown.md b/tests/testthat/_snaps/rmarkdown.md
index b9ba50fcd..afa816a05 100644
--- a/tests/testthat/_snaps/rmarkdown.md
+++ b/tests/testthat/_snaps/rmarkdown.md
@@ -9,34 +9,38 @@
 # render_rmarkdown yields useful error
 
     Code
-      render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = rmarkdown::html_document(
-        pandoc_args = "--fail-if-warnings"))
+      # Pandoc error
+      render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = format)
     Message
       Reading assets/pandoc-fail.Rmd
     Condition
-      Error in `render_rmarkdown()`:
-      ! Failed to render RMarkdown document.
-      x [WARNING] Could not fetch resource path-to-image.png Failing because there were warnings.
+      Error:
+      x Failed to render RMarkdown document.
+        [WARNING] Could not fetch resource path-to-image.png
+        Failing because there were warnings.
       Caused by error:
       ! pandoc document conversion failed with error 3
-
----
-
     Code
+      # R error
       render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
     Message
       Reading assets/r-fail.Rmd
     Condition
-      Error in `render_rmarkdown()`:
-      ! Failed to render RMarkdown document.
-      x Quitting from lines at lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
+      Error:
+      x Failed to render RMarkdown document.
+        
+        Quitting from lines at lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
       Caused by error:
       ! Error!
     Code
-      last_trace()
+      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html", new_process = FALSE)
+    Message
+      Reading assets/r-fail.Rmd
+      
+      Quitting from lines  at lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
     Condition
-      Error:
-      ! Can't show last error because no error was recorded yet
+      Error in `h()`:
+      ! Error!
 
 # render_rmarkdown styles ANSI escapes
 
diff --git a/tests/testthat/test-rmarkdown.R b/tests/testthat/test-rmarkdown.R
index 6e12d4794..d2bea3629 100644
--- a/tests/testthat/test-rmarkdown.R
+++ b/tests/testthat/test-rmarkdown.R
@@ -21,17 +21,16 @@ test_that("render_rmarkdown yields useful error", {
   tmp <- dir_create(file_temp())
   pkg <- list(src_path = test_path("."), dst_path = tmp, bs_version = 3)
 
-  # For pandoc
-  expect_snapshot(error = TRUE, {
-    render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html",
-        output_format = rmarkdown::html_document(pandoc_args = "--fail-if-warnings"))
-  })
+  format <- rmarkdown::html_document(pandoc_args = "--fail-if-warnings")
 
   expect_snapshot(error = TRUE, {
+    "Pandoc error"
+    render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = format)
+    
+    "R error"
     render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
-    last_trace()
+    render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html", new_process = FALSE)
   })
-
 })
 
 test_that("render_rmarkdown styles ANSI escapes", {

From f7fefb0ae91428741964d40a9dfa2779f17d2fea Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 09:07:41 -0500
Subject: [PATCH 6/9] Work around xfun issue

---
 tests/testthat/_snaps/rmarkdown.md |  4 ++--
 tests/testthat/test-rmarkdown.R    | 20 ++++++++++++--------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/tests/testthat/_snaps/rmarkdown.md b/tests/testthat/_snaps/rmarkdown.md
index afa816a05..91d04fd76 100644
--- a/tests/testthat/_snaps/rmarkdown.md
+++ b/tests/testthat/_snaps/rmarkdown.md
@@ -29,7 +29,7 @@
       Error:
       x Failed to render RMarkdown document.
         
-        Quitting from lines at lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
+        Quitting from lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
       Caused by error:
       ! Error!
     Code
@@ -37,7 +37,7 @@
     Message
       Reading assets/r-fail.Rmd
       
-      Quitting from lines  at lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
+      Quitting from lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
     Condition
       Error in `h()`:
       ! Error!
diff --git a/tests/testthat/test-rmarkdown.R b/tests/testthat/test-rmarkdown.R
index d2bea3629..ddda6f87e 100644
--- a/tests/testthat/test-rmarkdown.R
+++ b/tests/testthat/test-rmarkdown.R
@@ -23,14 +23,18 @@ test_that("render_rmarkdown yields useful error", {
 
   format <- rmarkdown::html_document(pandoc_args = "--fail-if-warnings")
 
-  expect_snapshot(error = TRUE, {
-    "Pandoc error"
-    render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = format)
-    
-    "R error"
-    render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
-    render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html", new_process = FALSE)
-  })
+  expect_snapshot(
+    {
+      "Pandoc error"
+      render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = format)
+      
+      "R error"
+      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
+      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html", new_process = FALSE)
+    },
+    error = TRUE,
+    # work around xfun bug
+    transform = function(x) gsub("lines  ?at lines", "lines", x))
 })
 
 test_that("render_rmarkdown styles ANSI escapes", {

From 85961d32e048f4c19c12ec997ab59d471b7deaa5 Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 09:13:32 -0500
Subject: [PATCH 7/9] Refactor tests; including traceback

---
 tests/testthat/_snaps/rmarkdown.md | 26 +++++++++++++++++---------
 tests/testthat/test-rmarkdown.R    | 29 ++++++++++++++++++++---------
 2 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/tests/testthat/_snaps/rmarkdown.md b/tests/testthat/_snaps/rmarkdown.md
index 91d04fd76..7ed6b9cef 100644
--- a/tests/testthat/_snaps/rmarkdown.md
+++ b/tests/testthat/_snaps/rmarkdown.md
@@ -6,10 +6,9 @@
       Reading assets/vignette-with-img.Rmd
       Writing `test.html`
 
-# render_rmarkdown yields useful error
+# render_rmarkdown yields useful error if pandoc fails
 
     Code
-      # Pandoc error
       render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = format)
     Message
       Reading assets/pandoc-fail.Rmd
@@ -20,27 +19,36 @@
         Failing because there were warnings.
       Caused by error:
       ! pandoc document conversion failed with error 3
+
+# render_rmarkdown yields useful error if R fails
+
     Code
-      # R error
-      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
+      # Test traceback
+      summary(expect_error(render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")))
     Message
       Reading assets/r-fail.Rmd
-    Condition
+    Output
+      <error/rlang_error>
       Error:
       x Failed to render RMarkdown document.
         
         Quitting from lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
       Caused by error:
       ! Error!
+      ---
+      Backtrace:
+          x
+       1. \-global f()
+       2.   \-global g()
+       3.     \-global h()
     Code
-      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html", new_process = FALSE)
+      # Just test that it works; needed for browser() etc
+      expect_error(render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html",
+        new_process = FALSE))
     Message
       Reading assets/r-fail.Rmd
       
       Quitting from lines 6-13 [unnamed-chunk-1] (r-fail.Rmd)
-    Condition
-      Error in `h()`:
-      ! Error!
 
 # render_rmarkdown styles ANSI escapes
 
diff --git a/tests/testthat/test-rmarkdown.R b/tests/testthat/test-rmarkdown.R
index ddda6f87e..8e618c1c9 100644
--- a/tests/testthat/test-rmarkdown.R
+++ b/tests/testthat/test-rmarkdown.R
@@ -13,7 +13,7 @@ test_that("render_rmarkdown copies image files in subdirectories", {
   )
 })
 
-test_that("render_rmarkdown yields useful error", {
+test_that("render_rmarkdown yields useful error if pandoc fails", {
   local_edition(3)
   skip_on_cran() # fragile due to pandoc dependency
   skip_if_no_pandoc("2.18")
@@ -22,19 +22,30 @@ test_that("render_rmarkdown yields useful error", {
   pkg <- list(src_path = test_path("."), dst_path = tmp, bs_version = 3)
 
   format <- rmarkdown::html_document(pandoc_args = "--fail-if-warnings")
+  expect_snapshot(
+    render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = format),
+    error = TRUE
+  )
+})
+
+test_that("render_rmarkdown yields useful error if R fails", {
+  local_edition(3)
+  skip_if_no_pandoc()
+
+  tmp <- dir_create(file_temp())
+  pkg <- list(src_path = test_path("."), dst_path = tmp, bs_version = 3)
 
   expect_snapshot(
     {
-      "Pandoc error"
-      render_rmarkdown(pkg, "assets/pandoc-fail.Rmd", "test.html", output_format = format)
-      
-      "R error"
-      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")
-      render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html", new_process = FALSE)
+      "Test traceback"
+      summary(expect_error(render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html")))
+
+      "Just test that it works; needed for browser() etc"
+      expect_error(render_rmarkdown(pkg, "assets/r-fail.Rmd", "test.html", new_process = FALSE))
     },
-    error = TRUE,
     # work around xfun bug
-    transform = function(x) gsub("lines  ?at lines", "lines", x))
+    transform = function(x) gsub("lines  ?at lines", "lines", x)
+  )
 })
 
 test_that("render_rmarkdown styles ANSI escapes", {

From 5f28931cd3f213d3f7c0d753a24d73405c7cc9e1 Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 09:25:27 -0500
Subject: [PATCH 8/9] Add `new_process` argument to build_article()

---
 R/build-articles.R    | 5 +++++
 man/build_articles.Rd | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/R/build-articles.R b/R/build-articles.R
index 8d858e41f..f82005c01 100644
--- a/R/build-articles.R
+++ b/R/build-articles.R
@@ -200,11 +200,15 @@ build_articles <- function(pkg = ".",
 #' @param name Name of article to render. This should be either a path
 #'   relative to `vignettes/` without extension, or `index` or `README`.
 #' @param data Additional data to pass on to template.
+#' @param new_process Build the article in a clean R process? The default,
+#'   `TRUE`, ensures that every article is build in a fresh environment, but
+#'   you may want to set it to `FALSE` to make debugging easier.
 build_article <- function(name,
                           pkg = ".",
                           data = list(),
                           lazy = FALSE,
                           seed = 1014L,
+                          new_process = TRUE,
                           quiet = TRUE) {
 
   pkg <- as_pkgdown(pkg)
@@ -293,6 +297,7 @@ build_article <- function(name,
     output_format = format,
     output_options = options,
     seed = seed,
+    new_process = new_process,
     quiet = quiet
   )
 }
diff --git a/man/build_articles.Rd b/man/build_articles.Rd
index 3f5b9c072..c1753785e 100644
--- a/man/build_articles.Rd
+++ b/man/build_articles.Rd
@@ -21,6 +21,7 @@ build_article(
   data = list(),
   lazy = FALSE,
   seed = 1014L,
+  new_process = TRUE,
   quiet = TRUE
 )
 
@@ -48,6 +49,10 @@ freshly generated section in browser.}
 relative to \verb{vignettes/} without extension, or \code{index} or \code{README}.}
 
 \item{data}{Additional data to pass on to template.}
+
+\item{new_process}{Build the article in a clean R process? The default,
+\code{TRUE}, ensures that every article is build in a fresh environment, but
+you may want to set it to \code{FALSE} to make debugging easier.}
 }
 \description{
 \code{build_articles()} renders each R Markdown file underneath \verb{vignettes/} and

From 6f30f5d25f8a8ed3b91f7319f6c65784186ed621 Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Mon, 15 Apr 2024 09:28:12 -0500
Subject: [PATCH 9/9] Add news bullet

---
 NEWS.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/NEWS.md b/NEWS.md
index 68ec2564f..80117fa44 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,6 @@
 # pkgdown (development version)
 
+* `build_article()` gains a new `new_process` argument which allows to build a vignette in the current process for debugging purposes. We've also improved the error messages and tracebacks if an article fails to build, hopefully also making debugging easier (#2438).
 * Preview links now work once again (#2435).
 * `build_home()` no longer renders Github issue and pull request templates (@hsloot, #2362)
 * It is now easier to preview parts of the website locally interactively. `build_reference_index()` and friends will call `init_site()` internally instead of erroring (@olivroy, #2329).