Disable tests checking the default PATH set by yash, which is used when the
PATH environment variable is unset.  These tests do not work on Guix because
the standard PATH relies on /usr/bin:/bin:…, which do not exist no Guix.

diff --git a/tests/command-p.tst b/tests/command-p.tst
index 47a4f29b..0ac459de 100644
--- a/tests/command-p.tst
+++ b/tests/command-p.tst
@@ -57,13 +57,6 @@ __IN__
 foo
 __OUT__
 
-test_o -e 0 'executing with standard path'
-PATH=
-command -p echo foo bar | command -p cat
-__IN__
-foo bar
-__OUT__
-
 (
 setup 'set -e'
 
@@ -272,16 +265,6 @@ PATH=
 command -V _no_such_command_
 __IN__
 
-test_x -e 0 'describing external command with standard path (-v)'
-PATH=
-command -pv cat
-__IN__
-
-test_x -e 0 'describing external command with standard path (-V)'
-PATH=
-command -pV cat
-__IN__
-
 )
 
 test_O -d -e 127 'executing non-existent command'