init: fix non-existing file check in csh

[gahr]

This fixes an issue whereas disabling the hook script by answering "no"
to the 2nd question of "opam init" you end with an init script that
tries to source the non-existing env hook script.

[gahr]

I guess the failure in appveyor is not related to my change

C:/projects/opam/bootstrap/ocaml/lib/ocaml/caml/misc.h:409:18: error: static declaration of ‘caml_snprintf’ follows non-static declaration
  409 | #define snprintf caml_snprintf
      |                  ^~~~~~~~~~~~~
C:/projects/opam/bootstrap/ocaml/lib/ocaml/caml/misc.h:408:12: note: previous declaration of ‘caml_snprintf’ was here
  408 | extern int caml_snprintf(char * buf, size_t size, const char * format, ...);
      |            ^~~~~~~~~~~~~

[rjbou]

Thanks for the PR.
On the issue you mention, do you have a failing log ?
Because it's not important that the script is written or no. In the init.sh (that is sourced in *shrc), there is a test on the availability of the script to source.
A sh generated one gives:

$ cat /tmp/opamroot/opam-init/init.sh
if [ -t 0 ]; then
  test -r /tmp/opamroot/opam-init/complete.sh && . /tmp/opamroot/opam-init/complete.sh > /dev/null 2> /dev/null || true

  test -r /tmp/opamroot/opam-init/env_hook.sh && . /tmp/opamroot/opam-init/env_hook.sh > /dev/null 2> /dev/null || true
fi

test -r /tmp/opamroot/opam-init/variables.sh && . /tmp/opamroot/opam-init/variables.sh > /dev/null 2> /dev/null || true

[gahr]

Ah thanks, I hadn't noticed the attemp to handle a non-existing file in init.(c)sh. That attempt is broken for csh, though.

opam/src/state/opamEnv.ml

Line 478 in 8ce5e42

Printf.sprintf "source %s >& /dev/null || true\n" (file f)

It tries to handle the error using || true, but in csh (citing the man page) "An error in a source at any level terminates all nested source commands." This causes a termination in sourcing the startup file ~/.cshrc.

I'll update the PR to properly check for the file existence in init.csh.

[gahr]

@rjbou need anything from my side?

[dra27]

Thanks!

[rjbou]

Oops, forgot to see the new version. lgtm, thanks @gahr!