[LyX/master] Improve error message.

[Richard Kimberly Heck]

commit 04f71516841ff8108c9d5d9d7b8ab2bfa6952f31
Author: Richard Kimberly Heck <rikih...@lyx.org>
Date:   Wed Apr 25 11:52:21 2018 -0400

    Improve error message.
---
 src/Buffer.cpp |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index 7569a4e..ee27f8f 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -4363,7 +4363,9 @@ Buffer::ExportStatus Buffer::doExport(string const & 
target, bool put_in_tempdir
        } else if (!lyxrc.tex_allows_spaces
                   && contains(filePath(), ' ')) {
                Alert::error(_("File name error"),
-                          _("The directory path to the document cannot contain 
spaces."));
+                       bformat(_("The directory path to the document\n%1$s\n"
+                           "contains spaces, but your TeX installation does "
+                           "not allow them."), from_ascii(filePath())));
                return ExportTexPathHasSpaces;
        } else {
                runparams.nice = false;