Specific error messages no longer returned

[jdblischak]

The recent updates to the error handling in the development versions of processx (r-lib/processx#335) and callr (#227) have broken some of my workflowr unit tests. My tests check for specific error messages, but these are no longer propagated via tryCatch(). Below is a reproducible example. Would it be possible to restore the previous behavior where the specific error message is retained?

f <- function() {
  tryCatch(
    callr::r_safe(function() stop("specific message")),
    error = function(e) e$message
  )
}

packageVersion("processx")
## [1] ‘3.6.0’
packageVersion("callr")
## [1] ‘3.7.0’
f()
## [1] "callr subprocess failed: specific message"

packageVersion("processx")
## [1] ‘3.6.0.9000’
packageVersion("callr")
## [1] ‘3.7.0.9000’
f()
## [1] "error in callr subprocess"

[gaborcsardi]

You need to use conditionMessage() to query the message of a condition object:

f2 <- function() {
  tryCatch(
    callr::r_safe(function() stop("specific message")),
    error = function(e) conditionMessage(e)
  )
}

❯ cat(f2())
! error in callr subprocess
Caused by error in `(function () …`:
! specific message

[jdblischak]

You need to use conditionMessage() to query the message of a condition object:

Confirmed. That fixed it. Thanks!

f2 <- function() {
  tryCatch(
    callr::r_safe(function() stop("specific message")),
    error = function(e) conditionMessage(e)
  )
}

packageVersion("processx")
## [1] ‘3.6.0’
packageVersion("callr")
## [1] ‘3.7.0’
f2()
## [1] "callr subprocess failed: specific message"

pak::pkg_install(c("r-lib/processx", "r-lib/callr"))

packageVersion("processx")
## [1] ‘3.6.0.9000’
packageVersion("callr")
## [1] ‘3.7.0.9000’
f2()
## [1] "! error in callr subprocess\nCaused by error in `(function () ...`:\n! specific message"
cat(f2())
## ! error in callr subprocess
## Caused by error in `(function () ...`:
## ! specific message