Found the following significant warnings:
  tools/px.c:19:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  ../inst/include/processx/unix-sockets.h:36:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  ../inst/include/processx/unix-sockets.c:118:29: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  supervisor/supervisor.c:144:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  client.c:128:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  processx-connection.h:181:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  processx-connection.h:189:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/processx-unix.h:36:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/processx-unix.h:37:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/processx-unix.h:38:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/processx-unix.h:39:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/processx-unix.h:55:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  processx.h:63:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  processx.h:70:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  cleancall.h:31:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  init.c:8:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  init.c:9:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  init.c:10:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  init.c:11:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  init.c:12:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  init.c:13:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  processx-connection.c:729:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  create-time.c:172:8: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../processx-connection.h:181:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../processx-connection.h:189:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:36:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:37:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:38:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:39:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../unix/processx-unix.h:55:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../processx.h:63:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../processx.h:70:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/childlist.c:17:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/childlist.c:80:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/../cleancall.h:31:1: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/processx.c:66:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/sigchld.c:111:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/sigchld.c:123:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/sigchld.c:131:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/sigchld.c:140:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/utils.c:60:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/utils.c:72:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  unix/utils.c:88:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
  cleancall.c:38:6: warning: function declaration isn’t a prototype [-Wstrict-prototypes]
See ‘/data/gannet/ripley/R/packages/tests-devel/processx.Rcheck/00install.out’ for details.