Re: [Libguestfs] [PATCH] common/mltools: Add a debug statement when we try to run a non-existent program.

On Monday, 19 November 2018 20:09:34 CET Richard W.M. Jones wrote: > Previously: > > $ virt-v2v -v -x -i disk fedora-28.img -o openstack -oo server-id=foo > virt-v2v: libguestfs 1.39.11fedora=29,release=1.fc29,libvirt (x86_64) > libvirt version: 4.5.0 > virt-v2v: error: openstack: precheck failed, there may be a problem with > authentication, see earlier error messages > rm -rf '/var/tmp/null.dTxRFN' > > Notice there is no "earlier error message". > > After this commit the error changes to: > > openstack: executable not found > virt-v2v: error: openstack: precheck failed, there may be a problem with > authentication, see earlier error messages > --- > common/mltools/tools_utils.ml | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/common/mltools/tools_utils.ml b/common/mltools/tools_utils.ml > index ad08d05eb..298d89b4d 100644 > --- a/common/mltools/tools_utils.ml > +++ b/common/mltools/tools_utils.ml > @@ -420,9 +420,11 @@ and do_run ?(echo_cmd = true) ?stdout_fd ?stderr_fd args = > Either (pid, app, stdout_fd, stderr_fd) > with > | Executable_not_found _ -> > - Or 127 > - | Unix.Unix_error (errcode, _, _) when errcode = Unix.ENOENT -> > - Or 127 > + debug "%s: executable not found" app; > + Or 127 > + | Unix.Unix_error (errcode, fn, _) when errcode = Unix.ENOENT -> > + debug "%s: %s: executable not found" app fn; > + Or 127 This is OK. Though, in the specific case of output_openstack#precheck I'd still check for the existance of the "openstack" executable first, just like what Python_script.error_unless_python_interpreter_found does. This way there is a better error message to cover the case described in the commit message, even in case -v is not passed.