Found the following significant warnings:
  tools/px.c:19:11: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ../inst/include/processx/unix-sockets.h:36:58: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ../inst/include/processx/unix-sockets.c:118:58: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  supervisor/supervisor.c:144:19: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  client.c:128:34: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./processx-connection.h:181:41: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./processx-connection.h:189:45: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./unix/processx-unix.h:36:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./unix/processx-unix.h:37:30: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./unix/processx-unix.h:38:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./unix/processx-unix.h:39:31: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./unix/processx-unix.h:55:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./processx.h:63:30: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./processx.h:70:35: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  ./cleancall.h:31:20: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  init.c:8:25: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  init.c:9:26: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  init.c:10:30: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  init.c:11:24: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  init.c:12:23: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  init.c:13:24: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  processx-connection.c:729:45: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  create-time.c:172:27: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../processx-connection.h:181:41: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../processx-connection.h:189:45: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:36:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:37:30: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:38:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:39:31: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:55:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../processx.h:63:30: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../processx.h:70:35: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/childlist.c:17:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/childlist.c:80:30: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/../cleancall.h:31:20: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/processx.c:66:26: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/sigchld.c:111:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/sigchld.c:123:30: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/sigchld.c:131:29: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/sigchld.c:140:31: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/utils.c:60:35: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/utils.c:72:23: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  unix/utils.c:88:24: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
  cleancall.c:38:20: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
See ‘/data/gannet/ripley/R/packages/tests-clang/processx.Rcheck/00install.out’ for details.