diff --git a/tool/build/deltaify.c b/tool/build/deltaify.c
index c2b93db8b..c2d420525 100644
--- a/tool/build/deltaify.c
+++ b/tool/build/deltaify.c
@@ -39,16 +39,16 @@ static void RelaySig(int sig, struct siginfo *si, struct ucontext *uc) {
 
 int main(int argc, char *argv[]) {
   FILE *f;
-  char *s;
   bool ok;
+  char *s, *p;
   int64_t micros;
   long double t1, t2;
   int ws, pipefds[2];
   setvbuf(stdout, malloc(BUFSIZ), _IOLBF, BUFSIZ);
   setvbuf(stderr, malloc(BUFSIZ), _IOLBF, BUFSIZ);
-  t1 = nowl();
   if (argc < 2) {
     f = stdin;
+    t1 = nowl();
   } else {
     sigset_t block, mask;
     struct sigaction saignore = {.sa_handler = SIG_IGN};
@@ -77,18 +77,25 @@ int main(int argc, char *argv[]) {
       execvp(argv[1], argv + 1);
       _exit(127);
     }
+    t1 = nowl();
     close(pipefds[1]);
     sigprocmask(SIG_SETMASK, &mask, NULL);
     CHECK((f = fdopen(pipefds[0], "r")));
     CHECK_NE(-1, setvbuf(f, malloc(4096), _IOLBF, 4096));
   }
-  for (;;) {
-    if (!(s = xgetline(f))) break;
+  if ((p = xgetline(f))) {
     t2 = nowl();
     micros = (t2 - t1) * 1e6;
     t1 = t2;
-    printf("%16ld %s", micros, s);
-    free(s);
+    printf("%16ld\n", micros);
+    do {
+      s = xgetline(f);
+      t2 = nowl();
+      micros = (t2 - t1) * 1e6;
+      t1 = t2;
+      printf("%16ld %s", micros, p);
+      free(p);
+    } while ((p = s));
   }
   ok = !ferror(f);
   if (argc < 2) return ok ? 0 : 1;
diff --git a/tool/build/deltaify2.c b/tool/build/deltaify2.c
deleted file mode 100644
index ad269e8b7..000000000
--- a/tool/build/deltaify2.c
+++ /dev/null
@@ -1,100 +0,0 @@
-/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
-│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ Permission to use, copy, modify, and/or distribute this software for         │
-│ any purpose with or without fee is hereby granted, provided that the         │
-│ above copyright notice and this permission notice appear in all copies.      │
-│                                                                              │
-│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
-│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
-│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
-│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
-│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
-│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
-│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
-│ PERFORMANCE OF THIS SOFTWARE.                                                │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/calls.h"
-#include "libc/calls/sigbits.h"
-#include "libc/calls/struct/sigaction.h"
-#include "libc/calls/struct/siginfo.h"
-#include "libc/calls/ucontext.h"
-#include "libc/errno.h"
-#include "libc/log/check.h"
-#include "libc/mem/mem.h"
-#include "libc/runtime/runtime.h"
-#include "libc/stdio/stdio.h"
-#include "libc/sysv/consts/sa.h"
-#include "libc/sysv/consts/sig.h"
-#include "libc/time/time.h"
-#include "libc/x/x.h"
-
-static int pid;
-
-static void RelaySig(int sig, struct siginfo *si, struct ucontext *uc) {
-  kill(pid, sig);
-}
-
-int main(int argc, char *argv[]) {
-  FILE *f;
-  bool ok;
-  char *s, *p;
-  int64_t micros;
-  long double t1, t2;
-  int ws, pipefds[2];
-  setvbuf(stdout, malloc(BUFSIZ), _IOLBF, BUFSIZ);
-  setvbuf(stderr, malloc(BUFSIZ), _IOLBF, BUFSIZ);
-  t1 = nowl();
-  if (argc < 2) {
-    f = stdin;
-  } else {
-    sigset_t block, mask;
-    struct sigaction saignore = {.sa_handler = SIG_IGN};
-    struct sigaction sadefault = {.sa_handler = SIG_DFL};
-    struct sigaction sarelay = {.sa_sigaction = RelaySig,
-                                .sa_flags = SA_RESTART};
-    sigemptyset(&block);
-    sigaddset(&mask, SIGINT);
-    sigaddset(&mask, SIGQUIT);
-    sigaddset(&mask, SIGCHLD);
-    sigprocmask(SIG_BLOCK, &block, &mask);
-    sigaction(SIGHUP, &sarelay, 0);
-    sigaction(SIGTERM, &sarelay, 0);
-    sigaction(SIGINT, &saignore, 0);
-    sigaction(SIGQUIT, &saignore, 0);
-    CHECK_NE(-1, pipe(pipefds));
-    CHECK_NE(-1, (pid = vfork()));
-    if (!pid) {
-      close(pipefds[0]);
-      dup2(pipefds[1], 1);
-      sigaction(SIGHUP, &sadefault, NULL);
-      sigaction(SIGTERM, &sadefault, NULL);
-      sigaction(SIGINT, &sadefault, NULL);
-      sigaction(SIGQUIT, &sadefault, NULL);
-      sigprocmask(SIG_SETMASK, &mask, NULL);
-      execvp(argv[1], argv + 1);
-      _exit(127);
-    }
-    close(pipefds[1]);
-    sigprocmask(SIG_SETMASK, &mask, NULL);
-    CHECK((f = fdopen(pipefds[0], "r")));
-    CHECK_NE(-1, setvbuf(f, malloc(4096), _IOLBF, 4096));
-  }
-  if ((p = xgetline(f))) {
-    do {
-      s = xgetline(f);
-      t2 = nowl();
-      micros = (t2 - t1) * 1e6;
-      t1 = t2;
-      printf("%16ld %s", micros, p);
-      free(p);
-    } while ((p = s));
-  }
-  ok = !ferror(f);
-  if (argc < 2) return ok ? 0 : 1;
-  fclose(f);
-  while (waitpid(pid, &ws, 0) == -1) CHECK_EQ(EINTR, errno);
-  return !WIFEXITED(ws) ? 128 + WTERMSIG(ws) : ok ? WEXITSTATUS(ws) : 1;
-}