If during the installation I select to install the packages ipa-pmincho-fonts,
ipa-pgothic-fonts, ipa-mincho-fonts, ipa-gothic-fonts, I found this error in
/var/log/zypp/history:

# 2016-04-20 20:35:11 ipa-pmincho-fonts-003.03-9.6.noarch.rpm installed ok
# Additional rpm output:
# /var/tmp/rpm-tmp.wT9ukS: line 2: dirname: command not found
# /var/tmp/rpm-tmp.wT9ukS: line 2: mkdir: command not found
# /var/tmp/rpm-tmp.wT9ukS: line 3: touch: command not found
# /var/tmp/rpm-tmp.wT9ukS: line 5: touch: command not found
# 
2016-04-20
20:35:11|install|ipa-pmincho-fonts|003.03-9.6|noarch||openSUSE-42.1-0|ec885fac6634a84e9ee02e342d17888b176f99f7|
# 2016-04-20 20:35:12 ipa-pgothic-fonts-003.03-9.6.noarch.rpm installed ok
# Additional rpm output:
# /var/tmp/rpm-tmp.D56Y5P: line 2: dirname: command not found
# /var/tmp/rpm-tmp.D56Y5P: line 2: mkdir: command not found
# /var/tmp/rpm-tmp.D56Y5P: line 3: touch: command not found
# /var/tmp/rpm-tmp.D56Y5P: line 5: touch: command not found
# 
2016-04-20
20:35:12|install|ipa-pgothic-fonts|003.03-9.6|noarch||openSUSE-42.1-0|c5479e381b1de6efc871fecf819cce298432c457|
# 2016-04-20 20:35:13 ipa-mincho-fonts-003.03-9.6.noarch.rpm installed ok
# Additional rpm output:
# /var/tmp/rpm-tmp.03Jefb: line 2: dirname: command not found
# /var/tmp/rpm-tmp.03Jefb: line 2: mkdir: command not found
# /var/tmp/rpm-tmp.03Jefb: line 3: touch: command not found
# /var/tmp/rpm-tmp.03Jefb: line 5: touch: command not found
# 
2016-04-20
20:35:13|install|ipa-mincho-fonts|003.03-9.6|noarch||openSUSE-42.1-0|7351796307f3bc60a11ebccb480f144a3e4d44a3|
# 2016-04-20 20:35:15 ipa-gothic-fonts-003.03-9.6.noarch.rpm installed ok
# Additional rpm output:
# /var/tmp/rpm-tmp.uQuiuA: line 2: dirname: command not found
# /var/tmp/rpm-tmp.uQuiuA: line 2: mkdir: command not found
# /var/tmp/rpm-tmp.uQuiuA: line 3: touch: command not found
# /var/tmp/rpm-tmp.uQuiuA: line 5: touch: command not found
# 
2016-04-20
20:35:15|install|ipa-gothic-fonts|003.03-9.6|noarch||openSUSE-42.1-0|3d60f2bcbd79f2932e283aeea75894aae832995b|

The problem is that ipa-pmincho-fonts, ipa-pgothic-fonts, ipa-mincho-fonts and
ipa-gothic-fonts are installed before coreutils and at that time the binaries
dirname, mkdir and touc used in the postinstall scriptlet, are not available
yet.

A possible fix is to add this lines in ipa-fonts.spec:

 %package -n ipa-pgothic-fonts
 Summary:        "Proportional Gothic" Japanese TrueType Font Made by IPA
 Group:          System/X11/Fonts
 Provides:       IPAPGothic = %{version}
 Provides:       scalable-font-ja
 Provides:       locale(ja)
 Obsoletes:      IPAPGothic <= 003.02
+Requires(pre):  coreutils

 %package -n ipa-gothic-fonts
 Summary:        "Gothic" Japanese TrueType Font Made by IPA
 Group:          System/X11/Fonts
 Provides:       IPAGothic = %{version}
 Provides:       scalable-font-ja
 Provides:       locale(ja)
 Obsoletes:      IPAGothic <= 003.02
+Requires(pre):  coreutils

 %package -n ipa-mincho-fonts
 Summary:        "Mincho" Japanese TrueType Font Made by IPA
 Group:          System/X11/Fonts
 Provides:       IPAMincho = %{version}
 Provides:       scalable-font-ja
 Provides:       locale(ja)
 Obsoletes:      IPAMincho <= 003.02
+Requires(pre):  coreutils

 %package -n ipa-pmincho-fonts
 Summary:        "Proportional Mincho" Japanese TrueType Font Made by IPA
 Group:          System/X11/Fonts
 Provides:       IPAPMincho = %{version}
 Provides:       scalable-font-ja
 Provides:       locale(ja)
 Obsoletes:      IPAPMincho <= 003.02
+Requires(pre):  coreutils