icebergr

• **A read made after another engine changed the schema without writing checked names against the wrong schema.** An ALTER TABLE ... RENAME COLUMN makes a new schema current while the current snapshot still names the old one, and iceberg-rust reads with the snapshot's. filter and select were checked against the table's current schema instead, so the renamed column could be selected by neither name, an added one passed the check and failed in planning, and a read that found no rows reported columns one that found rows did not. Names now resolve against the current snapshot's schema, and selecting a column only the newer schema has says why it is refused.
• **case_sensitive = FALSE broke filters on a table with both id and ID.** Each name was resolved to the right column here, then bound again by iceberg-rust, whose case-insensitive index keeps only one of the two, so a filter on the other failed with "Can't convert datum", or, between columns of the same type, read the wrong one. An empty result could also report the wrong one of the pair.
• **A decimal filter value below about 1e-5, or of 1e16 or more, was refused** as "exponent notation" although R had written it out in full, so a decimal(18, 8) column could not be compared with 0.00000002 at all.
• **An append to a table registered from a metadata file outside the table's metadata directory** wrote its Parquet and then failed to commit, leaving the files behind. It is now refused before anything is written, as a misnamed file already was. Both checks are now skipped for a REST catalog, whose server chooses metadata locations itself and may name them as it likes.
• **icebergr_create_table(location =) recorded the path as typed.** "~/tables/events" created a directory literally called ~ in the working directory, a relative path left the table readable only from there, and "" tried to create /metadata at the filesystem root. A local path is now expanded and made absolute, and an empty one is refused.
• An infinite Date or POSIXct in a filter is refused as infinite, rather than reaching iceberg-rust as a date to parse spelled "Inf".
• **icebergr_append(properties =) could make a table unreadable.** A property named operation was written as a second "operation" key in the table's metadata, after which no engine could load, register or append to the table again. Iceberg's own summary metrics were open to it too: a deleted-records property was subtracted into total-records. Every key Iceberg writes into a snapshot summary itself is now refused, and so is a name given twice.
• **A timestamp filter was a microsecond out.** Fractional seconds were truncated rather than rounded, and the double R holds for a microsecond timestamp is often just below it, so ts == x, with x read back from the same table, found no row for most values, and >= or < moved the boundary.
• **A POSIXlt filter value or as_of was read in the wrong zone.** Its wall-clock fields were taken as UTC, so a time from strptime(..., tz = "America/New_York") filtered or travelled four or five hours away from the instant it named.
• **A filter now keeps the rows R would, where NA and NaN are concerned.** It was handed to Iceberg with Iceberg's semantics, which differ from R's in four ways. x > 1 matched NaN, and only in files the scan read, since file statistics leave NaN out: of two identical NaN rows, one could come back and the other not. is.na(x) missed NaN. x == 0 missed a stored -0. And !(x %in% c(1, 2)) dropped the rows where x is NA, which R keeps because %in% is never NA. Checked against R's own evaluation of 3,200 random filters over columns holding all of these. String ordering still follows Iceberg's byte order, which is R's only in the C locale.
• **A column on the value side of a filter was read as a local variable.** filter = a > b, with b a column, compared a against whatever local b was in scope, silently. An Iceberg predicate cannot compare two columns, so this is now an error that says so.
• **A forked worker hung forever.** After any icebergr call in the parent, the first call in a parallel::mclapply() worker waited on runtime threads that do not survive fork(), with no error, and neither Ctrl-C nor the timeout could end it. It now fails at once and points at parallel::makeCluster().
• **A data frame naming a column twice lost the second one** on append. It is now refused.
• icebergr_register_table() accepts an object-storage location such as s3://..., which it used to refuse as a missing file, and no longer refuses every registration on a REST catalog whose warehouse is a name rather than a directory.
• A catalog property given as a number or a logical reaches iceberg-rust in the form it parses: 1e5 as "100000" rather than "1e+05", and TRUE as "true". A property passed twice through ... is refused rather than silently keeping the last.
• An S3:// warehouse is object storage whatever the case of its scheme, as it already was for forwarding credentials; it used to be put on the local disk.
• The cleartext check recognises http://LOCALHOST and the rest of 127.0.0.0/8 as loopback, and counts a header.Authorization, header.Cookie or header.X-Api-Key property as a credential.
• batch_size = 0 is refused rather than read as the default.
• A large append no longer runs under a single timeout. Rows reach the Parquet writer in slices, each its own call, so the five-minute ceiling bounds one slice rather than the whole upload. The files written are byte-identical.
• icebergr_snapshots() orders a v1 table's snapshots the same way on every call, and its summary JSON lists keys in sorted rather than hash order.
• An interrupt or a timeout while reading a batch is reported as such, rather than as "the Iceberg scan panicked".

Credentials and robustness

Closing the review findings tracked in

#2.

• **A credential is no longer sent over an unencrypted connection.** An http:// uri, or OAuth2 endpoint, is now an error when any credential property is populated, rather than putting Authorization: Bearer ... on the wire in the clear. A loopback address is exempt; set ICEBERGR_ALLOW_INSECURE_CREDENTIALS=true to override.
• **Ambient AWS_* credentials are forwarded only to object storage.** They were previously added to every catalog regardless of type, so a third-party REST catalog, which controls each table's location and can return its own s3.endpoint, could have the client sign requests to a host it chose using the user's keys. They now require storage = "s3", type = "glue", or an s3:// warehouse. The explicit ICEBERGR_S3_* variables are unaffected.
• **icebergr_register_table() gains confine, defaulting to TRUE.** A metadata file names absolute paths for its location, manifests and data files, so registering one from an untrusted source read whatever it nominated, and with the s3 feature compiled in it could make an outbound request from a nominally offline memory catalog. The file must now sit inside the catalog's warehouse; pass confine = FALSE for the previous behaviour.
• An error carrying an upstream message no longer leaks a credential the upstream echoed: user:password@ in a URL, and the value of a secret query or form parameter such as client_secret or X-Amz-Signature, are redacted, whether it is written key=value, key = value or as a JSON field, "client_secret": "...". The module already promised this and only delivered it for the key list.
• print() on a catalog redacts user:password@ in its uri.
• **Every await now has a five-minute ceiling.** A catalog that accepted the connection and never answered used to wedge the session permanently, since block_on parks R's thread and Ctrl-C is only checked between evaluations. ICEBERGR_TIMEOUT_SECONDS changes it; 0 disables it. The ceiling is per request, per record batch or per slice of an append, so a long scan or a large write is not truncated.
• ICEBERGR_WORKER_THREADS is clamped to 64. It had no upper bound, so a typo spawned threads until the allocator gave up.
• icebergr_scan_plan() drains the plan into its five output columns as tasks arrive, rather than collecting every FileScanTask and then walking the collection five times. One row per task is inherent, but a task carries its schema, its predicate and its delete-file list, none of which this function returns, so holding all of them alongside the columns was avoidable.
• **Ctrl-C now interrupts a blocking catalog or storage call.** block_on parks R's own thread and R only tests its interrupt flag between evaluations, so an interrupt used to do nothing at all until the call finished. The future is now polled in 200 ms slices, and between slices, back on R's thread and outside the runtime, R's flag is read and turned into an ordinary error. The timeout above remains the backstop for where Ctrl-C cannot reach, such as a non-interactive session. Closes #12.
• **An interrupt or a timeout now reports itself as a plain R error.** Both are raised from Rust as panics, because the value they have to abandon is the future's own type and there is nothing to return in its place, and a panic prints a banner naming a source line and offering a backtrace before extendr converts it. Pressing Ctrl-C should not look like a crash, so the panic hook recognises this package's own deliberate aborts and stays quiet for them. A genuine bug, such as an index out of bounds or an unwrap() on NULL, still prints in full.

Installation

• **Installs on Alpine Linux and other musl systems.** vendor.tar.xz was compressed with a 128 MiB dictionary, and BusyBox's tar, which those systems use, refuses anything over 64 MiB, reporting only "corrupted data". CRAN's musl check recorded exactly that for 0.1.0. It is now 64 MiB, and tools/vendor.R checks the archive it writes.
• **rustc 1.88 or newer, down from 1.92**, measured by building the vendored tree with 1.88.0 and running the test suite on it. CRAN's r-oldrel-macos-arm64 builder carries 1.91.1, so 0.1.0 could not be installed there. uuid is held below 1.27, the first release to need 1.89.
• Every Rust dependency is at its latest compatible version. iceberg-rust is 0.10.1, whose Rust code is identical to 0.10.0's. rustls 0.23.45 fixes RUSTSEC-2026-0285, tokio 1.53.2 fixes several runtime and timer bugs, and for the optional s3 and glue features h2 0.4.19 fixes RUSTSEC-2026-0258. Those two features still carry quick-xml 0.39.4, affected by RUSTSEC-2026-0194 and RUSTSEC-2026-0195, because opendal 0.57, the version iceberg-rust 0.10 requires, depends on it.
• icebergr_spec_support() now reads the iceberg-rust and arrow versions it reports out of Cargo.lock when the package is built, rather than from strings typed into the source that a dependency bump could leave stale, and arrow_version carries the patch number.

Documentation

• ?icebergr_catalog now says that a REST or Glue handle does not contact the server: iceberg-rust connects on the first operation that needs it, so a mistyped uri, an unreachable host or an unset credential all return a handle and fail later, at icebergr_list_namespaces() or icebergr_table(). The troubleshooting section of vignette("catalog-configuration") gained the same note, since the symptom reads as a fault in those functions.
• Corrections that were wrong in 0.1.0 or in this release's drafts: vignette("catalog-configuration") gave glue.region as the Glue region property, where the Glue client reads region_name, and showed SigV4 settings for a REST catalog that iceberg-rust 0.10.0 does not support and silently ignores. vignette("time-travel") said a rollback removes a snapshot-log entry (it adds one) and that iceberg-rust lacks snapshot expiry (it lacks rollback). The description no longer says that going through DuckDB rules out writes, which DuckDB has supported for REST catalogs since 1.4.
• Seven vignettes, up from two. table-format explains what a table format is as distinct from a file format, and what the Hive directory convention could not do; pushdown shows the three levels a filter acts at and how to confirm each with icebergr_scan_plan() rather than assume it; time-travel covers snapshot history and the two ways as_of is easy to misread; writing covers appends, creation and registration, and why the operations it cannot do are refused before anything reaches the warehouse; types covers the R, Arrow and Iceberg correspondence and the five cases that need care. Each carries a bibliography.
• icebergr_create_table()'s behaviour is now documented rather than implied: it reads a schema off the data frame and writes **no rows**, leaving a table with no snapshot at all.
• A pkgdown site at <https://pursuitofdatascience.github.io/icebergr/>.
• A package logo, generated by data-raw/logo.R.
• A much shorter README, with the packaging analysis it used to carry left in FEASIBILITY.md, where it was already duplicated.