Ceph

As of Version 2.0 of the SPDX Specification, "GPL-2.0-with-autoconf-exception" is not a valid license.

Quoting from https://spdx.org/licenses/

<blockquote>
Release 2.0 of the SPDX Specification introduces License Expression Syntax that supports the ability to identify common variations of SPDX-identified licenses without the need to define each potential variation as a distinct license on the SPDX License List. This new syntax supports the ability to use a simple “+” operator after a license short identifier to indicate “or later version” (e.g. GPL-2.0+). It also supports the ability to declare an SPDX-identified license exception using the “WITH” operator (e.g. GPL-2.0+ WITH Autoconf-exception-2.0). SPDX has defined a list of license exceptions to use after the “WITH” operator. As a result, a number of licenses formerly included in the SPDX License List have been deprecated as licenses, and correct usage employs the License Expression Syntax as of v2.0. The URL to each deprecated license still exists and those license pages have been updated to note the deprecation. Other licenses may have been deprecated for reasons noted.
</blockquote>