certificate error message during emerge

[minou666]

I was making an update on a beagleboard X15 (AM5729 Processor from TI) and got a certificate not valid message

suzie ~ # emerge -uavDN @world

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild  N     ] dev-lang/swig-3.0.12::lang-kit  USE="pcre -ccache -doc" 7 959 KiB
[ebuild  r  U  ] dev-libs/nettle-3.5.1:0/7::security-kit [3.4.1:0/6.2::security-kit] USE="gmp -abi_riscv_lp64 -abi_riscv_lp64d -doc -neon -static-libs -test" 1 943 KiB
[ebuild  rR    ] net-libs/gnutls-3.6.7:0/30::core-kit  USE="cxx idn nls openssl tls-heartbeat -abi_riscv_lp64 -abi_riscv_lp64d (-dane) -doc -examples -guile -pkcs11 -seccomp -sslv2 -sslv3 -static-libs -test -test-full -tools -valgrind" 7 963 KiB
[ebuild  N     ] app-crypt/libb2-0.98.1-r1::nokit  USE="openmp -native-cflags -static-libs" 275 KiB
[ebuild     U  ] dev-python/cryptography-2.8-r1::python-modules-kit [2.6.1::python-modules-kit] USE="-idna -libressl -test" PYTHON_TARGETS="python2_7 python3_7 (-pypy3) -python3_6 (-pypy%) (-python3_5%)" 493 KiB
[ebuild  N     ] app-crypt/gpgme-1.13.0:1/11::nokit  USE="cxx python -common-lisp -qt5 -static-libs" PYTHON_TARGETS="python2_7 python3_7 -python3_5 -python3_6" 1 778 KiB
[ebuild     U  ] app-portage/portage-utils-0.80_pre20190620::core-kit [0.74-r1::core-kit] USE="nls openmp%* qmanifest%* -libressl% -static" 1 721 KiB

Total: 7 packages (3 upgrades, 3 new, 1 reinstall), Size of downloads: 22 130 KiB

The following packages are causing rebuilds:

  (dev-libs/nettle-3.5.1:0/7::security-kit, ebuild scheduled for merge) causes rebuilds for:
    (net-libs/gnutls-3.6.7:0/30::core-kit, ebuild scheduled for merge)

Would you like to merge these packages? [Yes/No] Yes

>>> Verifying ebuild manifests

>>> Emerging (1 of 7) dev-lang/swig-3.0.12::lang-kit
 * Fetching files in the background.
 * To view fetch progress, run in another terminal:
 * tail -f /var/log/emerge-fetch.log
>>> Downloading 'https://fastpull-us.funtoo.org/distfiles/swig-3.0.12.tar.gz'
--2019-08-25 20:55:11--  https://fastpull-us.funtoo.org/distfiles/swig-3.0.12.tar.gz
Resolving fastpull-us.funtoo.org... 192.150.253.88
Connecting to fastpull-us.funtoo.org|192.150.253.88|:443... connected.
ERROR: cannot verify fastpull-us.funtoo.org's certificate, issued by ‘CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US’:
  Issued certificate not yet valid.
To connect to fastpull-us.funtoo.org insecurely, use `--no-check-certificate'.
>>> Downloading 'http://download.sourceforge.net/swig/swig-3.0.12.tar.gz'
--2019-08-25 20:55:12--  http://download.sourceforge.net/swig/swig-3.0.12.tar.gz
Resolving download.sourceforge.net... 216.105.38.13
Connecting to download.sourceforge.net|216.105.38.13|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location: http://downloads.sourceforge.net/project/swig/swig/swig-3.0.12/swig-3.0.12.tar.gz [following]
--2019-08-25 20:55:12--  http://downloads.sourceforge.net/project/swig/swig/swig-3.0.12/swig-3.0.12.tar.gz
Resolving downloads.sourceforge.net... 216.105.38.13
Reusing existing connection to download.sourceforge.net:80.
HTTP request sent, awaiting response... 302 Found
Location: https://iweb.dl.sourceforge.net/project/swig/swig/swig-3.0.12/swig-3.0.12.tar.gz [following]
--2019-08-25 20:55:12--  https://iweb.dl.sourceforge.net/project/swig/swig/swig-3.0.12/swig-3.0.12.tar.gz
Resolving iweb.dl.sourceforge.net... 2607:f748:10:12::5f:2, 192.175.120.182
Connecting to iweb.dl.sourceforge.net|2607:f748:10:12::5f:2|:443... connected.
ERROR: cannot verify iweb.dl.sourceforge.net's certificate, issued by ‘CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US’:
  Issued certificate not yet valid.
To connect to iweb.dl.sourceforge.net insecurely, use `--no-check-certificate'.
!!! Couldn't download 'swig-3.0.12.tar.gz'. Aborting.
 * Fetch failed for 'dev-lang/swig-3.0.12', Log file:
 *  '/var/tmp/portage/dev-lang/swig-3.0.12/temp/build.log'

>>> Failed to emerge dev-lang/swig-3.0.12, Log file:

>>>  '/var/tmp/portage/dev-lang/swig-3.0.12/temp/build.log'

 * Messages for package dev-lang/swig-3.0.12:

 * Fetch failed for 'dev-lang/swig-3.0.12', Log file:
 *  '/var/tmp/portage/dev-lang/swig-3.0.12/temp/build.log'