ERROR: OPatch failed because of Path problem.Some commands below are not in your path: Command= fuser

Oracle Interim Patch Installer version 1.0.0.0.64
Copyright (c) 2011 Oracle Corporation. All Rights Reserved..

Oracle recommends you to use the latest OPatch version
and read the OPatch documentation available in the OPatch/docs
directory for usage. For information about the latest OPatch and
other support-related issues, refer to document ID 293369.1
available on My Oracle Support (https://myoraclesupport.oracle.com)

Oracle Home           : /apps/upgmgr/tech_st/10.1.2
Oracle Home Inventory : /apps/upgmgr/tech_st/10.1.2/inventory
Central Inventory     : /apps/upgmgr/inst/apps/NJVCUPG_oralnxaptst/admin/oraInventory
   from               : /apps/upgmgr/tech_st/10.1.2/oraInst.loc
OUI location          : /apps/upgmgr/tech_st/10.1.2/oui
OUI shared library    : /apps/upgmgr/tech_st/10.1.2/oui/lib/linux/liboraInstaller.so
Java location         : /apps/upgmgr/tech_st/10.1.2/jdk/jre/bin/java
Log file location     : /apps/upgmgr/tech_st/10.1.2/.patch_storage//*.log

Some commands below are not in your path:
  Command= fuser
  Extra Search Path= /sbin/fuser, /usr/sbin/fuser
  Path= /apps/upgmgr/inst/apps/NJVCUPG_oralnxaptst/admin/scripts:/apps/upgmgr/tech_st/10.1.3/perl/bin:/apps/upgmgr/tech_st/10.1.2/bin:/apps/upgmgr/apps_st/appl/fnd/12.0.0/bin:/apps/upgmgr/apps_st/appl/ad/12.0.0/bin:/apps/upgmgr/tech_st/10.1.3/appsutil/jdk/jre/bin::/apps/upgmgr/tech_st/10.1.2/bin:/usr/bin:/usr/sbin:/apps/upgmgr/tech_st/10.1.3/appsutil/jdk/jre/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/apps/upgmgr/bin:/apps/upgmgr/tech_st/10.1.2/OPatch:/apps/upgmgr/tech_st/10.1.3/appsutil/jdk/bin:/apps/upgmgr/tech_st/10.1.3/ant/bin:/apps/upgmgr/bin

ERROR: OPatch failed because of Path problem.

Solution:

I installed the psmisc package that includes the fuser program