  We report the first detection of CO J = 3-2 around a truly metal-poor evolved
star. RU Vulpeculae is modelled to have Teff ~ 3620 K, L ~ 3128 +/- 516 L_Sun,
log(g) = 0.0 ~ 0.2 dex and [Fe/H] = -1.3 to -1.0 dex, and is modelled to have
recently undergone a thermal pulse. Its infrared flux has approximately doubled
over 35 years. ALMA observations show the 3-2 line is narrow (half-width
~1.8-3.5 km/s). The 2-1 line is much weaker: it is not confidently detected.
Spectral-energy-distribution fitting indicates very little circumstellar
absorption, despite its substantial mid-infrared emission. A VISIR mid-infrared
spectrum shows features typical of previously observed metal-poor stars,
dominated by a substantial infrared excess but with weak silicate and
(possibly) Al2O3 emission. A lack of resolved emission, combined with weak 2!1
emission, indicates the dense circumstellar material is truncated at large
radii. We suggest that rapid dust condensation is occurring, but with an
aspherical geometry (e.g., a disc or clumps) that does not obscure the star. We
compare with T UMi, a similar star which is currently losing its dust.
