A very interesting short piece about spending the 1971-72 academic year in Paris – Trevor Pateman, “Roland Barthes: Writer, Intellectual, and also Professor”, Barthes Studies, 2025 (open access). It briefly mentions Foucault:

But Barthes’ preferences were very similar to Foucault’s who succeeded in conducting seminars despite his Collège de France obligation to lecture publicly to anyone who chose to attend. He simply grilled everyone who packed into a large room for the first session, asking why they were there and whether they were willing to engage with a collaborative project, studying the parricide Pierre Rivière’s memoir. The grilling got rid of the unserious or, at least, the timid.

He also mentions attending classes by other French academics, including Derrida, Lacan and Lévi-Strauss, and Jakobson lecturing at the College de France, which I write about here. What a time to be in Paris! The short piece also includes images of a letter and a postcard from Barthes.