Well, never mind. I added the two lines by hand:

~$ rtl_fm -f 89000000 -R -s 1000000 -g 0 - | baudline -stdin -samplerate 1000000 -quadrature -flipcomplex -channels 2 -format le16

Found 1 device(s):

0: Realtek, RTL2838UHIDIR, SN: 00000013

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle

Found Rafael Micro R820T tuner

Oversampling input by: 2x.

Oversampling output by: 1x.

Buffer size: 4.10ms

Tuned to 89500000 Hz.

Sampling at 2000000 Hz.

Output at 1000000 Hz.

Exact sample rate is: 2000000.052982 Hz

rtlsdr_set_tuner_gain_mode(1) -> 0

rtlsdr_set_tuner_gain(0) -> 0

Tuner gain set to 0.00 dB.

~$ rtl_fm -f 89000000 -R -s 1000000 -g 30 - | baudline -stdin -samplerate 1000000 -quadrature -flipcomplex -channels 2 -format le16