precompilepkgs: fix error reporting (#53862)

Author: IanButterworth

base/precompilation.jl

@@ -333,6 +333,8 @@ struct PkgPrecompileError <: Exception
     msg::String
 end
 Base.showerror(io::IO, err::PkgPrecompileError) = print(io, err.msg)
+Base.showerror(io::IO, err::PkgPrecompileError, bt; kw...) = Base.showerror(io, err) # hide stacktrace
+
 # This needs a show method to make `julia> err` show nicely
 Base.show(io::IO, err::PkgPrecompileError) = print(io, "PkgPrecompileError: ", err.msg)
 
@@ -821,7 +823,7 @@ function precompilepkgs(pkgs::Vector{String}=String[];
                             close(std_pipe.in) # close pipe to end the std output monitor
                             wait(t_monitor)
                             if err isa ErrorException || (err isa ArgumentError && startswith(err.msg, "Invalid header in cache file"))
-                                failed_deps[pkg_config] = (strict || is_direct_dep) ? string(sprint(showerror, err), "\n", strip(get(std_outputs, pkg, ""))) : ""
+                                failed_deps[pkg_config] = (strict || is_direct_dep) ? string(sprint(showerror, err), "\n", strip(get(std_outputs, pkg_config, ""))) : ""
                                 delete!(std_outputs, pkg_config) # so it's not shown as warnings, given error report
                                 !fancyprint && lock(print_lock) do
                                     println(io, " "^9, color_string("  ✗ ", Base.error_color()), name)
@@ -944,7 +946,7 @@ function precompilepkgs(pkgs::Vector{String}=String[];
                 end
             else
                 println(io)
-                error(err_msg)
+                throw(PkgPrecompileError(err_msg))
             end
         end
     end