After intalling libsecret the launcher did open but after few seconds just crashed with the "longjmp..." error, as the OP have reported. Looking for the error in google I came across the same error with the curl program (which probably the launcher is using), and how to resolve it. It turns out that curl must be emerged with the "adns" USE flag. It seems that after doing that the launcher is working fine for me.
J. R.
Hello,
I was having the same issue, also gentoo linux.
After intalling libsecret the launcher did open but after few seconds just crashed with the "longjmp..." error, as the OP have reported. Looking for the error in google I came across the same error with the curl program (which probably the launcher is using), and how to resolve it. It turns out that curl must be emerged with the "adns" USE flag. It seems that after doing that the launcher is working fine for me.