diff --git a/tests/guix-archive.sh b/tests/guix-archive.sh
index 4c5eea05cf..e796c62f9a 100644
--- a/tests/guix-archive.sh
+++ b/tests/guix-archive.sh
@@ -44,8 +44,7 @@ cmp "$archive" "$archive_alt"
 # Check the exit value upon import.
 guix archive --import < "$archive"
 
-if guix archive something-that-does-not-exist
-then false; else true; fi
+! guix archive something-that-does-not-exist
 
 # This one must not be listed as missing.
 guix build guile-bootstrap > "$archive"
@@ -62,8 +61,7 @@ cmp "$archive" "$archive_alt"
 
 # This is not a valid store file name, so an error.
 echo something invalid > "$archive"
-if guix archive --missing < "$archive"
-then false; else true; fi
+! guix archive --missing < "$archive"
 
 # Check '--extract'.
 guile -c "(use-modules (guix serialization))
@@ -79,5 +77,4 @@ guix archive -t < "$archive" | grep "^D /share/guile"
 guix archive -t < "$archive" | grep "^x /bin/guile"
 guix archive -t < "$archive" | grep "^r /share/guile.*/boot-9\.scm"
 
-if echo foo | guix archive --authorize
-then false; else true; fi
+! echo foo | guix archive --authorize
diff --git a/tests/guix-build-branch.sh b/tests/guix-build-branch.sh
index c5b07e07c6..79aa06a58f 100644
--- a/tests/guix-build-branch.sh
+++ b/tests/guix-build-branch.sh
@@ -58,5 +58,4 @@ guix gc -R "$v0_1_0_drv" | grep guile-gcrypt-8fe64e8 # this is the tag ID
 test "$v0_1_0_drv" != "$latest_drv"
 test "$v0_1_0_drv" != "$orig_drv"
 
-if guix build guix --with-commit=guile-gcrypt=000 -d
-then false; else true; fi
+! guix build guix --with-commit=guile-gcrypt=000 -d
diff --git a/tests/guix-build.sh b/tests/guix-build.sh
index ec2f736ccb..6dbb53206e 100644
--- a/tests/guix-build.sh
+++ b/tests/guix-build.sh
@@ -24,8 +24,7 @@
 guix build --version
 
 # Should fail.
-if guix build -e +;
-then false; else true; fi
+! guix build -e +
 
 # Source-less packages are accepted; they just return nothing.
 guix build -e '(@ (gnu packages bootstrap) %bootstrap-glibc)' -S
@@ -178,7 +177,7 @@ cat > "$module_dir/foo.scm" <<EOF
     (inputs (quasiquote (("sed" ,sed))))))  ;unbound variable
 EOF
 
-if guix build package-with-something-wrong -n; then false; else true; fi
+! guix build package-with-something-wrong -n
 guix build package-with-something-wrong -n 2> "$module_dir/err" || true
 grep "unbound" "$module_dir/err"		     # actual error
 grep "forget.*(gnu packages base)" "$module_dir/err" # hint
@@ -222,7 +221,7 @@ test "`guix build --log-file guile-bootstrap`" = "$log"
 test "`guix build --log-file $out`" = "$log"
 
 # Should fail because the name/version combination could not be found.
-if guix build hello-0.0.1 -n; then false; else true; fi
+! guix build hello-0.0.1 -n
 
 # Keep a symlink to the result, registered as a root.
 result="t-result-$$"
@@ -231,8 +230,7 @@ guix build -r "$result"					\
 test -x "$result/bin/guile"
 
 # Should fail, because $result already exists.
-if guix build -r "$result" -e '(@@ (gnu packages bootstrap) %bootstrap-guile)'
-then false; else true; fi
+! guix build -r "$result" -e '(@@ (gnu packages bootstrap) %bootstrap-guile)'
 
 rm -f "$result"
 
@@ -270,8 +268,7 @@ drv2=`guix build hello -d --with-input=gcc=gcc-toolchain`
 test "$drv1" != "$drv2"
 guix gc -R "$drv2" | grep `guix build -d gcc-toolchain`
 
-if guix build guile --with-input=libunistring=something-really-silly
-then false; else true; fi
+! guix build guile --with-input=libunistring=something-really-silly
 
 # Deprecated/superseded packages.
 test "`guix build superseded -d`" = "`guix build bar -d`"
@@ -279,10 +276,8 @@ test "`guix build superseded -d`" = "`guix build bar -d`"
 # Parsing package names and versions.
 guix build -n time		# PASS
 guix build -n time@1.9		# PASS, version found
-if guix build -n time@3.2;	# FAIL, version not found
-then false; else true; fi
-if guix build -n something-that-will-never-exist; # FAIL
-then false; else true; fi
+! guix build -n time@3.2	# FAIL, version not found
+! guix build -n something-that-will-never-exist # FAIL
 
 # Invoking a monadic procedure.
 guix build -e "(begin
@@ -354,5 +349,4 @@ export GUIX_BUILD_OPTIONS
 guix build emacs
 
 GUIX_BUILD_OPTIONS="--something-completely-crazy"
-if guix build emacs;
-then false; else true; fi
+! guix build emacs
diff --git a/tests/guix-daemon.sh b/tests/guix-daemon.sh
index b58500966b..330ad68835 100644
--- a/tests/guix-daemon.sh
+++ b/tests/guix-daemon.sh
@@ -224,7 +224,7 @@ daemon_pid=$!
 GUIX_DAEMON_SOCKET="guix://$tcp_socket"
 export GUIX_DAEMON_SOCKET
 
-if guix gc; then false; else true; fi
+! guix gc
 
 unset GUIX_DAEMON_SOCKET
 kill "$daemon_pid"
diff --git a/tests/guix-download.sh b/tests/guix-download.sh
index 30f55fbe2b..5475d43e60 100644
--- a/tests/guix-download.sh
+++ b/tests/guix-download.sh
@@ -23,14 +23,11 @@
 guix download --version
 
 # Make sure it fails here.
-if guix download http://does.not/exist
-then false; else true; fi
+! guix download http://does.not/exist
 
-if guix download unknown://some/where;
-then false; else true; fi
+! guix download unknown://some/where;
 
-if guix download /does-not-exist
-then false; else true; fi
+! guix download /does-not-exist
 
 # This one should succeed.
 guix download "file://$abs_top_srcdir/README"
@@ -46,5 +43,4 @@ GUIX_DAEMON_SOCKET="/nowhere" guix download -o "$output" \
 cmp "$output" "$abs_top_srcdir/README"
 
 # This one should fail.
-if guix download "file:///does-not-exist" "file://$abs_top_srcdir/README"
-then false; else true; fi
+! guix download "file:///does-not-exist" "file://$abs_top_srcdir/README"
diff --git a/tests/guix-environment.sh b/tests/guix-environment.sh
index 2faf38df06..f8be48f0c0 100644
--- a/tests/guix-environment.sh
+++ b/tests/guix-environment.sh
@@ -60,7 +60,7 @@ guix environment --bootstrap --ad-hoc guile-bootstrap --pure	\
 grep '^PATH=' "$tmpdir/a"
 grep '^GUIX_TEST_ABC=' "$tmpdir/a"
 grep '^GUIX_TEST_DEF=' "$tmpdir/a"
-if grep '^GUIX_TEST_XYZ=' "$tmpdir/a"; then false; else true; fi
+! grep '^GUIX_TEST_XYZ=' "$tmpdir/a"
 
 # Make sure the exit value is preserved.
 if guix environment --bootstrap --ad-hoc guile-bootstrap --pure \
@@ -194,8 +194,7 @@ then
     done
 
     # 'make-boot0' itself must not be listed.
-    if guix gc --references "$profile" | grep make-boot0
-    then false; else true; fi
+    ! guix gc --references "$profile" | grep make-boot0
 
     # Make sure that the shell spawned with '--exec' sees the same environment
     # as returned by '--search-paths'.
@@ -212,8 +211,7 @@ then
     test "x$make_boot0_debug" != "x"
 
     # Make sure the "debug" output is not listed.
-    if guix gc --references "$profile" | grep "$make_boot0_debug"
-    then false; else true; fi
+    ! guix gc --references "$profile" | grep "$make_boot0_debug"
 
     # Compute the build environment for the initial GNU Make, but add in the
     # bootstrap Guile as an ad-hoc addition.
diff --git a/tests/guix-gc.sh b/tests/guix-gc.sh
index 8284287730..f40619876d 100644
--- a/tests/guix-gc.sh
+++ b/tests/guix-gc.sh
@@ -36,11 +36,11 @@ unset out
 # For some operations, passing extra arguments is an error.
 for option in "" "-C 500M" "--verify" "--optimize" "--list-roots"
 do
-    if guix gc $option whatever; then false; else true; fi
+    ! guix gc $option whatever
 done
 
 # This should fail.
-if guix gc --verify=foo; then false; else true; fi
+! guix gc --verify=foo
 
 # Check the references of a .drv.
 drv="`guix build guile-bootstrap -d`"
@@ -51,8 +51,7 @@ guix gc --references "$drv" | grep -e -bash
 guix gc --references "$out"
 guix gc --references "$out/bin/guile"
 
-if guix gc --references /dev/null;
-then false; else true; fi
+! guix gc --references /dev/null;
 
 # Check derivers.
 guix gc --derivers "$out" | grep "$drv"
@@ -72,8 +71,7 @@ test -f "$drv" && test -L guix-gc-root
 guix gc --list-roots | grep "$PWD/guix-gc-root"
 
 guix gc --list-live | grep "$drv"
-if guix gc --delete "$drv";
-then false; else true; fi
+! guix gc --delete "$drv";
 
 rm guix-gc-root
 guix gc --list-dead | grep "$drv"
@@ -84,8 +82,7 @@ guix gc --delete "$drv"
 guix gc -C 1KiB
 
 # Check trivial error cases.
-if guix gc --delete /dev/null;
-then false; else true; fi
+! guix gc --delete /dev/null;
 
 # Bug #19757
 out="`guix build guile-bootstrap`"
diff --git a/tests/guix-git-authenticate.sh b/tests/guix-git-authenticate.sh
index 1c76e240b5..8ebbea398b 100644
--- a/tests/guix-git-authenticate.sh
+++ b/tests/guix-git-authenticate.sh
@@ -46,9 +46,8 @@ v1_0_0_signer="3CE4 6455 8A84 FDC6 9DB4  0CFB 090B 1199 3D9A EBB5" # civodul
 v1_0_1_commit="d68de958b60426798ed62797ff7c96c327a672ac"
 
 # This should fail because these commits lack '.guix-authorizations'.
-if guix git authenticate "$v1_0_0_commit" "$v1_0_0_signer" \
-	--cache-key="$cache_key" --end="$v1_0_1_commit";
-then false; else true; fi
+! guix git authenticate "$v1_0_0_commit" "$v1_0_0_signer" \
+       --cache-key="$cache_key" --end="$v1_0_1_commit"
 
 # This should work thanks to '--historical-authorizations'.
 guix git authenticate "$v1_0_0_commit" "$v1_0_0_signer" 	\
diff --git a/tests/guix-graph.sh b/tests/guix-graph.sh
index ccb4933c88..666660ab4b 100644
--- a/tests/guix-graph.sh
+++ b/tests/guix-graph.sh
@@ -60,7 +60,7 @@ guix graph -t references guile-bootstrap | grep guile-bootstrap
 guix graph -e '(@ (gnu packages bootstrap) %bootstrap-guile)' \
     | grep guile-bootstrap
 
-if guix graph -e +; then false; else true; fi
+! guix graph -e +
 
 # Try passing store file names.
 
@@ -77,14 +77,13 @@ cmp "$tmpfile1" "$tmpfile2"
 # Try package transformation options.
 guix graph git | grep 'label = "openssl'
 guix graph git --with-input=openssl=libressl | grep 'label = "libressl'
-if guix graph git --with-input=openssl=libressl | grep 'label = "openssl'
-then false; else true; fi
+! guix graph git --with-input=openssl=libressl | grep 'label = "openssl'
 
 # Try --load-path
 guix graph -L $module_dir dummy | grep 'label = "dummy'
 
 # Displaying shortest paths (or lack thereof).
-if guix graph --path emacs vim; then false; else true; fi
+! guix graph --path emacs vim
 
 path="\
 emacs
diff --git a/tests/guix-hash.sh b/tests/guix-hash.sh
index 3538b9aeda..346355539f 100644
--- a/tests/guix-hash.sh
+++ b/tests/guix-hash.sh
@@ -34,8 +34,7 @@ test `guix hash -f base32 /dev/null` = 4oymiquy7qobjgx36tejs35zeqt24qpemsnzgtfes
 test `guix hash -H sha512 -f hex /dev/null` = cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e
 test `guix hash -H sha1 -f base64 /dev/null` = "2jmj7l5rSw0yVb/vlWAYkK/YBwk="
 
-if guix hash -H abcd1234 /dev/null;
-then false; else true; fi
+! guix hash -H abcd1234 /dev/null
 
 mkdir "$tmpdir"
 echo -n executable > "$tmpdir/exe"
@@ -46,13 +45,11 @@ mkdir "$tmpdir/subdir"
 test `guix hash -r "$tmpdir"` = 10k1lw41wyrjf9mxydi0is5nkpynlsvgslinics4ppir13g7d74p
 
 # Without '-r', this should fail.
-if guix hash "$tmpdir"
-then false; else true; fi
+! guix hash "$tmpdir"
 
 # This should fail because /dev/null is a character device, which
 # the archive format doesn't support.
-if guix hash -r /dev/null
-then false; else true; fi
+! guix hash -r /dev/null
 
 # Adding a .git directory
 mkdir "$tmpdir/.git"
@@ -65,6 +62,5 @@ test `guix hash -r $tmpdir` = 0a50z04zyzf7pidwxv0nwbj82pgzbrhdy9562kncnvkcfvb48m
 test `guix hash -r $tmpdir -x` = 10k1lw41wyrjf9mxydi0is5nkpynlsvgslinics4ppir13g7d74p
 
 # Without '-r', this should fail.
-if guix hash "$tmpdir"
-then false; else true; fi
+! guix hash "$tmpdir"
 
diff --git a/tests/guix-lint.sh b/tests/guix-lint.sh
index ebe79efb84..fdf548fbf1 100644
--- a/tests/guix-lint.sh
+++ b/tests/guix-lint.sh
@@ -58,24 +58,19 @@ grep_warning ()
 # 3) the description has a single space following the end-of-sentence period.
 
 out=`guix lint -c synopsis,description dummy 2>&1`
-if [ `grep_warning "$out"` -ne 3 ]
-then false; else true; fi
+test `grep_warning "$out"` -eq 3
 
 out=`guix lint -c synopsis dummy 2>&1`
-if [ `grep_warning "$out"` -ne 2 ]
-then false; else true; fi
+test `grep_warning "$out"` -eq 2
 
 out=`guix lint -c description dummy 2>&1`
-if [ `grep_warning "$out"` -ne 1 ]
-then false; else true; fi
+test `grep_warning "$out"` -eq 1
 
 out=`guix lint -c description,synopsis dummy 2>&1`
-if [ `grep_warning "$out"` -ne 3 ]
-then false; else true; fi
+test `grep_warning "$out"` -eq 3
 
-if guix lint -c synopsis,invalid-checker dummy 2>&1 | \
+guix lint -c synopsis,invalid-checker dummy 2>&1 | \
    grep -q 'invalid-checker: invalid checker'
-then true; else false; fi
 
 # Make sure specifying multiple packages works.
 guix lint -c inputs-should-be-native dummy dummy@42 dummy
@@ -85,8 +80,7 @@ guix lint -c inputs-should-be-native dummy dummy@42 dummy
 unset GUIX_PACKAGE_PATH
 
 out=`guix lint -L $module_dir -c synopsis,description dummy 2>&1`
-if [ `grep_warning "$out"` -ne 3 ]
-then false; else true; fi
+test `grep_warning "$out"` -eq 3
 
 # Make sure specifying multiple packages works.
 guix lint -L $module_dir -c inputs-should-be-native dummy dummy@42 dummy
diff --git a/tests/guix-pack-relocatable.sh b/tests/guix-pack-relocatable.sh
index b8d36a02c6..a960ecd209 100644
--- a/tests/guix-pack-relocatable.sh
+++ b/tests/guix-pack-relocatable.sh
@@ -77,8 +77,7 @@ then
     grep 'GNU sed' "$test_directory/output"
 
     # Check whether the exit code is preserved.
-    if run_without_store "$test_directory/Bin/sed" --does-not-exist;
-    then false; else true; fi
+    ! run_without_store "$test_directory/Bin/sed" --does-not-exist
 
     chmod -Rf +w "$test_directory"; rm -rf "$test_directory"/*
 else
diff --git a/tests/guix-pack.sh b/tests/guix-pack.sh
index 39b64791e2..0339221ac2 100644
--- a/tests/guix-pack.sh
+++ b/tests/guix-pack.sh
@@ -45,8 +45,7 @@ guix gc -R "$drv" | grep "`guix build coreutils -d --no-grafts`"
 drv="`guix pack idutils -d --no-grafts --target=arm-linux-gnueabihf`"
 guix gc -R "$drv" | \
     grep "`guix build idutils --target=arm-linux-gnueabihf -d --no-grafts`"
-if guix gc -R "$drv" | grep "`guix build idutils -d --no-grafts`";
-then false; else true; fi
+! guix gc -R "$drv" | grep "`guix build idutils -d --no-grafts`"
 
 # Build a tarball with no compression.
 guix pack --compression=none --bootstrap guile-bootstrap
diff --git a/tests/guix-package-aliases.sh b/tests/guix-package-aliases.sh
index e24bff3a56..e4ddace057 100644
--- a/tests/guix-package-aliases.sh
+++ b/tests/guix-package-aliases.sh
@@ -36,26 +36,22 @@ guix install --bootstrap guile-bootstrap -p "$profile"
 test -x "$profile/bin/guile"
 
 # Make sure '-r' isn't passed as-is to 'guix package'.
-if guix install -r guile-bootstrap -p "$profile" --bootstrap
-then false; else true; fi
+! guix install -r guile-bootstrap -p "$profile" --bootstrap
 test -x "$profile/bin/guile"
 
 guix upgrade --version
 guix upgrade -n
 guix upgrade gui.e -n
-if guix upgrade foo bar -n;
-then false; else true; fi
+! guix upgrade foo bar -n;
 
 guix remove --version
 guix remove --bootstrap guile-bootstrap -p "$profile"
 ! test -x "$profile/bin/guile"
 test `guix package -p "$profile" -I | wc -l` -eq 0
 
-if guix remove -p "$profile" this-is-not-installed --bootstrap
-then false; else true; fi
+! guix remove -p "$profile" this-is-not-installed --bootstrap
 
-if guix remove -i guile-bootstrap -p "$profile" --bootstrap
-then false; else true; fi
+! guix remove -i guile-bootstrap -p "$profile" --bootstrap
 
 guix search '\<board\>' game | grep '^name: gnubg'
 
@@ -64,7 +60,7 @@ guix show guile
 guix show python@3 | grep "^name: python"
 
 # "python@2" exists but is deprecated; make sure it doesn't show up.
-if guix show python@2; then false; else true; fi
+! guix show python@2
 
 # Specifying multiple packages.
 output="`guix show sed grep | grep ^name:`"
diff --git a/tests/guix-package-net.sh b/tests/guix-package-net.sh
index 3876701fa2..6d21c6cff6 100644
--- a/tests/guix-package-net.sh
+++ b/tests/guix-package-net.sh
@@ -95,10 +95,8 @@ test "`guix package -p "$profile" -l | cut -f1 | grep guile | head -n1`" \
      = "  guile-bootstrap"
 
 # Exit with 1 when a generation does not exist.
-if guix package -p "$profile" --list-generations=42;
-then false; else true; fi
-if guix package -p "$profile" --switch-generation=99;
-then false; else true; fi
+! guix package -p "$profile" --list-generations=42
+! guix package -p "$profile" --switch-generation=99
 
 # Remove a package.
 guix package --bootstrap -p "$profile" -r "guile-bootstrap"
@@ -174,8 +172,7 @@ test -z "`guix package -p "$profile" -l 3`"
 rm "$profile"
 guix package --bootstrap -p "$profile" -i guile-bootstrap
 guix package --bootstrap -p "$profile_alt" -i gcc-bootstrap
-if guix package -p "$profile" --search-paths | grep LIBRARY_PATH
-then false; fi
+! guix package -p "$profile" --search-paths | grep LIBRARY_PATH
 guix package -p "$profile" -p "$profile_alt" --search-paths \
      | grep "LIBRARY_PATH.*$profile/lib.$profile_alt/lib"
 
diff --git a/tests/guix-package.sh b/tests/guix-package.sh
index 1f955257be..1a95b8e9a4 100644
--- a/tests/guix-package.sh
+++ b/tests/guix-package.sh
@@ -36,8 +36,7 @@ rm -f "$profile" "$tmpfile"
 trap 'rm -f "$profile" "$profile.lock" "$profile-"[0-9]* "$tmpfile"; rm -rf "$module_dir" t-home-'"$$" EXIT
 
 # Use `-e' with a non-package expression.
-if guix package --bootstrap -e +;
-then false; else true; fi
+! guix package --bootstrap -e +
 
 # Install a store item and make sure the version and output in the manifest
 # are correct.
@@ -62,8 +61,7 @@ test -f "$profile/bin/guile"
 
 # Collisions are properly flagged (in this case, 'g-wrap' propagates
 # guile@2.2, which conflicts with guile@2.0.)
-if guix package --bootstrap -n -p "$profile" -i g-wrap guile@2.0
-then false; else true; fi
+! guix package --bootstrap -n -p "$profile" -i g-wrap guile@2.0
 
 guix package --bootstrap -n -p "$profile" -i g-wrap guile@2.0 \
      --allow-collisions
@@ -78,8 +76,7 @@ test "`guix package -p "$profile" --search-paths | wc -l`" = 1  # $PATH
   type -P rm )
 
 # Exit with 1 when a generation does not exist.
-if guix package -p "$profile" --delete-generations=42;
-then false; else true; fi
+! guix package -p "$profile" --delete-generations=42
 
 # Exit with 0 when trying to delete the zeroth generation.
 guix package -p "$profile" --delete-generations=0
@@ -92,15 +89,12 @@ guix package --bootstrap -i "glibc:debug" -p "$profile" -n
 
 # Make sure nonexistent outputs are reported.
 guix package --bootstrap -i "guile-bootstrap:out" -p "$profile" -n
-if guix package --bootstrap -i "guile-bootstrap:does-not-exist" -p "$profile" -n;
-then false; else true; fi
-if guix package --bootstrap -i "guile-bootstrap:does-not-exist" -p "$profile";
-then false; else true; fi
+! guix package --bootstrap -i "guile-bootstrap:does-not-exist" -p "$profile" -n
+! guix package --bootstrap -i "guile-bootstrap:does-not-exist" -p "$profile"
 
 # Make sure we get an error when trying to remove something that's not
 # installed.
-if guix package --bootstrap -r something-not-installed -p "$profile";
-then false; else true; fi
+! guix package --bootstrap -r something-not-installed -p "$profile"
 
 # Check whether `--list-available' returns something sensible.
 guix package -p "$profile" -A 'gui.*e' | grep guile
@@ -112,8 +106,8 @@ guix package --show=guile | grep "^name: guile"
 guix package --show=texlive
 
 # Fail for non-existent packages or package/version pairs.
-if guix package --show=does-not-exist; then false; else true; fi
-if guix package --show=emacs@42; then false; else true; fi
+! guix package --show=does-not-exist
+! guix package --show=emacs@42
 
 # Search.
 LC_MESSAGES=C
@@ -157,22 +151,19 @@ guix package --search="" > /dev/null
 # There's no generation older than 12 months, so the following command should
 # have no effect.
 generation="`readlink_base "$profile"`"
-if guix package -p "$profile" --delete-generations=12m;
-then false; else true; fi
+! guix package -p "$profile" --delete-generations=12m
 test "`readlink_base "$profile"`" = "$generation"
 
 # The following command should not delete the current generation, even though
 # it matches the given pattern (see <http://bugs.gnu.org/19978>.)  And since
 # there's nothing else to delete, it should just fail.
 guix package --list-generations -p "$profile"
-if guix package --bootstrap -p "$profile" --delete-generations=1..
-then false; else true; fi
+! guix package --bootstrap -p "$profile" --delete-generations=1..
 test "`readlink_base "$profile"`" = "$generation"
 
 # Make sure $profile is a GC root at this point.
 real_profile="`readlink -f "$profile"`"
-if guix gc -d "$real_profile"
-then false; else true; fi
+! guix gc -d "$real_profile"
 test -d "$real_profile"
 
 # Now, let's remove all the symlinks to $real_profile, and make sure
@@ -238,16 +229,15 @@ done
 
 # Check whether '-p ~/.guix-profile' makes any difference.
 # See <http://bugs.gnu.org/17939>.
-if test -e "$HOME/.guix-profile-0-link"; then false; fi
-if test -e "$HOME/.guix-profile-1-link"; then false; fi
+! test -e "$HOME/.guix-profile-0-link"
+! test -e "$HOME/.guix-profile-1-link"
 guix package --bootstrap -p "$HOME/.guix-profile" -i guile-bootstrap
-if test -e "$HOME/.guix-profile-1-link"; then false; fi
+! test -e "$HOME/.guix-profile-1-link"
 guix package --bootstrap --roll-back -p "$HOME/.guix-profile"
-if test -e "$HOME/.guix-profile-0-link"; then false; fi
+! test -e "$HOME/.guix-profile-0-link"
 
 # Extraneous argument.
-if guix package install foo-bar;
-then false; else true; fi
+! guix package install foo-bar
 
 # Make sure the "broken pipe" doesn't yield an error.
 # Note: 'pipefail' is a Bash-specific option.
@@ -336,8 +326,7 @@ cat > "$module_dir/package.scm"<<EOF
 
 (define my-package coreutils)   ;returns *unspecified*
 EOF
-if guix package --bootstrap --install-from-file="$module_dir/package.scm"
-then false; else true; fi
+! guix package --bootstrap --install-from-file="$module_dir/package.scm"
 
 rm "$module_dir/package.scm"