Verified 2.31-0ubuntu9.2 on Focal: root@ff-icc:~# /opt/intel/oneapi/compiler/2021.1.2/linux/bin/intel64/icc -c test.c In file included from /opt/intel/oneapi/compiler/2021.1.2/linux/bin/intel64/../../compiler/include/icc/tgmath.h(25), from test.c(1): /usr/include/tgmath.h(54): error: #error directive: "Unsupported combination of types for ." # error "Unsupported combination of types for ." ^ compilation aborted for test.c (code 2) root@ff-icc:~# dpkg -l libc6-dev Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-===============-===============-============-===================================================== ii libc6-dev:amd64 2.31-0ubuntu9.1 amd64 GNU C Library: Development Libraries and Header Files root@ff-icc:~# sed -i s/backports/proposed/ /etc/apt/sources.list root@ff-icc:~# apt update Hit:1 http://archive.ubuntu.com/ubuntu focal InRelease Hit:2 http://archive.ubuntu.com/ubuntu focal-updates InRelease Get:3 http://archive.ubuntu.com/ubuntu focal-proposed InRelease [267 kB] Hit:4 http://security.ubuntu.com/ubuntu focal-security InRelease Get:5 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 Packages [213 kB] Hit:6 https://apt.repos.intel.com/oneapi all InRelease Get:7 http://archive.ubuntu.com/ubuntu focal-proposed/main Translation-en [51.6 kB] Get:8 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 c-n-f Metadata [2524 B] Get:9 http://archive.ubuntu.com/ubuntu focal-proposed/restricted amd64 Packages [36.5 kB] Get:10 http://archive.ubuntu.com/ubuntu focal-proposed/restricted Translation-en [5460 B] Get:11 http://archive.ubuntu.com/ubuntu focal-proposed/restricted amd64 c-n-f Metadata [116 B] Get:12 http://archive.ubuntu.com/ubuntu focal-proposed/universe amd64 Packages [51.9 kB] Get:13 http://archive.ubuntu.com/ubuntu focal-proposed/universe Translation-en [24.3 kB] Get:14 http://archive.ubuntu.com/ubuntu focal-proposed/universe amd64 c-n-f Metadata [1612 B] Get:15 http://archive.ubuntu.com/ubuntu focal-proposed/multiverse amd64 Packages [704 B] Get:16 http://archive.ubuntu.com/ubuntu focal-proposed/multiverse Translation-en [3752 B] Get:17 http://archive.ubuntu.com/ubuntu focal-proposed/multiverse amd64 c-n-f Metadata [192 B] Fetched 658 kB in 1s (831 kB/s) Reading package lists... Done Building dependency tree Reading state information... Done 25 packages can be upgraded. Run 'apt list --upgradable' to see them. root@ff-icc:~# apt install libc6-dev Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libfreetype6 libpciaccess0 Use 'apt autoremove' to remove them. The following additional packages will be installed: libc-dev-bin libc6 Suggested packages: glibc-doc The following packages will be upgraded: libc-dev-bin libc6 libc6-dev 3 upgraded, 0 newly installed, 0 to remove and 22 not upgraded. Need to get 5306 kB of archives. After this operation, 6144 B of additional disk space will be used. Do you want to continue? [Y/n] Get:1 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 libc6-dev amd64 2.31-0ubuntu9.2 [2520 kB] Get:2 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 libc-dev-bin amd64 2.31-0ubuntu9.2 [71.8 kB] Get:3 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 libc6 amd64 2.31-0ubuntu9.2 [2715 kB] Fetched 5306 kB in 1s (4268 kB/s) Preconfiguring packages ... (Reading database ... 49023 files and directories currently installed.) Preparing to unpack .../libc6-dev_2.31-0ubuntu9.2_amd64.deb ... Unpacking libc6-dev:amd64 (2.31-0ubuntu9.2) over (2.31-0ubuntu9.1) ... Preparing to unpack .../libc-dev-bin_2.31-0ubuntu9.2_amd64.deb ... Unpacking libc-dev-bin (2.31-0ubuntu9.2) over (2.31-0ubuntu9.1) ... Preparing to unpack .../libc6_2.31-0ubuntu9.2_amd64.deb ... Unpacking libc6:amd64 (2.31-0ubuntu9.2) over (2.31-0ubuntu9.1) ... Setting up libc6:amd64 (2.31-0ubuntu9.2) ... Setting up libc-dev-bin (2.31-0ubuntu9.2) ... Setting up libc6-dev:amd64 (2.31-0ubuntu9.2) ... Processing triggers for man-db (2.9.1-1) ... Processing triggers for libc-bin (2.31-0ubuntu9.1) ... root@ff-icc:~# /opt/intel/oneapi/compiler/2021.1.2/linux/bin/intel64/icc -c test.c root@ff-icc:~# dpkg -l libc6-dev Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-===============-===============-============-===================================================== ii libc6-dev:amd64 2.31-0ubuntu9.2 amd64 GNU C Library: Development Libraries and Header Files root@ff-icc:~# cat test.c #include