* Package:    x11-libs/librfm-5.3.16.3-r1
 * Repository: gentoo
 * USE:        abi_x86_64 amd64 elibc_glibc kernel_linux userland_GNU
 * FEATURES:   network-sandbox preserve-libs sandbox splitdebug userpriv usersandbox
>>> Unpacking source...
>>> Unpacking librfm5-5.3.16.3.tar.bz2 to /var/tmp/portage/x11-libs/librfm-5.3.16.3-r1/work
>>> Source unpacked in /var/tmp/portage/x11-libs/librfm-5.3.16.3-r1/work
>>> Preparing source in /var/tmp/portage/x11-libs/librfm-5.3.16.3-r1/work/librfm5-5.3.16.3 ...
sed: -e expression #1, char 66: unknown option to `s'
 * ERROR: x11-libs/librfm-5.3.16.3-r1::gentoo failed (prepare phase):
 *   (no error message)
 * 
 * Call stack:
 *     ebuild.sh, line 125:  Called src_prepare
 *   environment, line 2331:  Called die
 * The specific snippet of code:
 *       sed -i -e "s:-O2:${CFLAGS}:" m4/rfm-conditionals.m4 || die;
 * 
 * If you need support, post the output of `emerge --info '=x11-libs/librfm-5.3.16.3-r1::gentoo'`,
 * the complete build log and the output of `emerge -pqv '=x11-libs/librfm-5.3.16.3-r1::gentoo'`.
 * The complete build log is located at '/var/log/portage/x11-libs:librfm-5.3.16.3-r1:20200226-062416.log'.
 * For convenience, a symlink to the build log is located at '/var/tmp/portage/x11-libs/librfm-5.3.16.3-r1/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/x11-libs/librfm-5.3.16.3-r1/temp/environment'.
 * Working directory: '/var/tmp/portage/x11-libs/librfm-5.3.16.3-r1/work/librfm5-5.3.16.3'
 * S: '/var/tmp/portage/x11-libs/librfm-5.3.16.3-r1/work/librfm5-5.3.16.3'